fig. 1), Dr. Bowerbank figures faithfully a fragment of the latter, which he finds not to be Myliusia callocyathes, but, although very like in outward appearance to it, totally different in structure; hence he calls it "Myliusia Grayi."

Having subsequently had to examine this sponge for the late Dr. Gray, I saw that its minute structure (fig. 10) was like that of the fossil species figured by Schmidt (Atlantisch. Spongienf. Taf. ii. fig. 16) under the general appellation of fossil spicules from "Scyphia and Ventriculites (Ann. & Mag. Nat. Hist. 1873, vol. xii. p. 365). Next I identified the lantern-like knot of Myliusia Grayi with Mr. W. J. Sollas's figures of the structure of the Ventriculites (Proc. Geol. Soc. Lond. 1872, p. 65, fig. 2); lastly, with the late Mr. J. Toulmin Smith's representations of the structure of the "Ventriculidæ of the Chalk" (Ann. & Mag. Nat. Hist. 1847, vol. xx. pl. vii. figs. 8-14.

I next observed the lantern-like knot among the "Cretaceous Microzoa of the North of Ireland," figured by Mr. J. Wright (Report of Belfast Naturalists' Field-Club, 1873-74, Append. iii., published 1875, pl. iii. fig. 7). After this I found it myself among fossil sponge-spicules from the Mid Eocene of Brussels, kindly sent me by M. Ernest Vanden Broeck. And it again appears under another form in the beautiful illustrations of the structure of Coloptychium agaricoides by Prof. Karl Zittel of Munich ('Ueber Coloptychium,' München, 1876, Taf. iii. figs. 7-12). Finally in 1876 I obtained a slice of a Ventriculite from Mr. Ed. Charlesworth, of the Strand, London, and identified it therein myself.

It was then that I saw the desirability of illustrating the only known living specimen of the kind, viz. Myliusia Grayi in the British Museum; and having obtained permission of Dr. Günther for this purpose, I have done my best to publish it; for the specimen is very small, and, from its insignificant appearance and dirty colour, would be very likely to be lost sight of altogether, since it does not present the attractive bright glassy aspect and sarcodeless character usually possessed by the vitreous sponges after they have passed through the the hands of the dealer.

Although Myliusia Grayi presents the convoluted cerebriform appearance of M. callocyathes, yet its minute structure is totally different, inasmuch as the knots or junctions of the fibre in the latter are solid and round, not hollow and lantern-shaped as in M. Grayi. Again, the general structure of M. Grayi, although convoluted, is massive and labyrinthic throughout, not cup-shaped or hollow in the axis as that of the Ventriculites; while Coloptychium consists of radiating tubes more or less

branched round a hollow axis or stem, which in the horizontal section resembles Ventriculites.

In the evolution of the lantern-like joint it may be observed that this commences on a sexradiate spicule (fig. 9, c), the centre of which becomes the centre of the lantern, while the structureless sarcode, which here very much resembles that of the Rhizopoda, creeps crookedly and fungus-like from one point of the sexradiate direct to the other, thus marking out the lines of a trapezium (fig. 9,6). After this, subsidiary pseudopodal prolongations are continued from the fixed ends of the threads respectively to the arms of the sexradiate, which in a reticulated form thus further unite the two and act as additional stays to the main ones. After this the silicifying sarcode still goes on adding layer after layer to the original structure, until the whole becomes greatly thickened and the interstices of the reticulation reduced to eight spaces as before mentioned, so as almost to obscure the cross of the original sexradiate in the centre, which, although also thickened by the silicifying sarcode, still remains intact. Thus, in short, the sexradiate becomes as much imbedded in the vitreous sarcode as if it were in radiate fibre.

The fringe of spicules which is or, rather, was (for it now lies in loose pieces about the specimen) attached to the growing margins of the circular and gutter-like openings, is also composed of sexradiates, but much larger than those upon which the lanterns are formed; and while five of their arms interknit proximally with the body-structure of the wall of the tubular tortuous channel, the sixth is free and very long comparatively; while the fringe thus formed is still further lengthened by the presence of many (?acerates) much thicker and longer than any of the rays of the sexradiate, and which, by their uneven surface, seem to represent that form of acerate, so common among the Hexactinellida generally, in which the spines are long and all inclined one way—that is, inwardly in situ (fig. 5). Still this is of course conjecture; for I have never been able to find more than a fragment of the shaft of these, but never connected with any cross piece so as to indicate that they belonged to a sexradiate spicule. However, the surface is so mutilated that the fragments of this fringe are, as just stated, all loose upon the specimen, and only by their pencil-like form here and there, in which the spicules are held together in their natural position by the dried sarcode, show the manner in which they were arranged when attached to the margin of the circular and gutter-like openings of the tubular channels or passages.

The rosettes are large (especially when compared with those

of the last species, as the illustrations figs. 7 and 14 respectively, which are drawn to the same scale, indicate) and numerous, particularly towards the surface; and the little bundles of minute undulating, fine, hair-like acerates (fig. 10, g), which I have so often figured in the Esperiada and other sponges of the Holorhaphidota, are also very plentiful, and very frequently present a distinct, tricurvate or bow-like form (fig. 15).

I need not allude further to the differences between this and the foregoing species, viz. Eurete farreopsis, as these may be gathered from the descriptions and illustrations respectively.

In the formation of the lanterns from the sarcodic substance one cannot help being struck with the fact that, while this part of the sponge appears to be Radiolarian, the addition of the Spongozoa makes the sponge. This "radiolarian" sarcode is the "intercellular substance, which forms the bond of union between the cells" in sponges, that I described and delineated in Spongilla in 1849 (Ann. & Mag. Nat. Hist. vol. iv. pp. 87 and 91, pl. iv. fig. 2) as possessing the polymorphic power and contracting vesicles of an Amaba.

EXPLANATION OF PLATE IX.

Fig. 1. Eurete farreopsis, n. sp., natural size; from a photograph. Fig. 2. The same. Five diagrams, to show the mode of growth, commencing with a, simple cylinder with circular orifice; b, the same, with orifice expanded; c, the same, with orifice become funnelshaped; d, with orifice elliptical and contracted in the centre, like the figure 8; e, approximated sides united so as to form a simple cylinder on each side, with circular orifice, ff, like that

of a. Fig. 3. The same, minute structure of the wall, magnified. a a a a, fibre bb bb, knots or points of junction of the fibre; c c c, occasional spines on the same; d d, minute hexactinellid spicules which the fibre has attached to itself; e, scopuline spicule; f, small rosette, common form; g, large rosette, occasional form. Scale 1-24th to 1-1800th inch.

Fig. 4. The same, form of staple sexradiate spicule.

Fig. 5. The same, spined acerate.

Fig. 6. The same, scopuline spicule. a, shaft; b, arm; c, head of arm, more magnified, to show the form and arrangement of the spines. Fig. 7. The same, usual form of the rosette. (The third axis, which would be vertical to the others, has been omitted for perspicuity.)

N.B. Figs. 4 to 7 inclusively are on the scale of 1-24th to 1-6000th of an inch.

Fig. 8. Myliusia Grayi, Bk., natural size; from a photograph. Fig. 9. The same: four knots or trapezoids, magnified, to show their earliest appearance. a, trapezoid; b, reticulated threads of silicifying sarcode extending from point to point of the sexradiate spicule, c. (The vertical axis of the latter omitted here also for perspicuity.)

Fig. 10. The same: four knots or trapezoids, magnified, to show their form under full development. a, trapezoid with reticulated

threads of silicifying sarcode all run together into solid fibre, thus enveloping the sexradiate spicule, c, in the centre, which is otherwise hollow; d, spine or arm of sexradiate increased in size by the silicifying sarcode, but not enveloped in the fibre; e, end of vertical arm of sexradiate truncated; f, rosette; g, bundle of minute hair-like undulating acerates, frequently tricurvate or bow-shaped; hh, cylindrical intervals or channels between the trapezoids; i, lantern-like hole, reduced to eight in each trapezoid.

N.B. Although both these figures, viz. 9 and 10, are drawn upon the same scale (viz. 1-24th to 1-1800th inch), it must not be assumed that the trapezoids are as regularly formed throughout the mass; hence they must, to a certain extent, be viewed more or less as diagrammatic.

Fig. 11. The same: oblique view of the trapezoid of fig. 9, showing all the arms of the sexradiate spicule within the reticulated threads of silicifying sarcode.

Fig. 12. The same: diagram of trapezoid to show the sexradiate cross as it exists in the trapezoid of fig. 10.

Fig. 13. The same: staple form of dermal sexradiate, scale 1-24th to 1

1800th inch.

Fig. 14. The same: rosette, more magnified.

Fig. 15. The same: tricurvates, more magnified.

Fig. 16. The same: large sexradiate spicule of the fringe.

Fig. 17. The same: fragment of large uneven spicule in the fringe.

X.-List of the Species of Crustacea collected by the Rev. A. E. Eaton at Spitzbergen in the Summer of 1873, with their Localities and Notes. By EDWARD J. MIERS, F.L.S., F.Z.S., Assistant in the Zoological Department, British Museum.

A SMALL collection of Crustacea, made by the Rev. A. E. Eaton during a voyage with B. Leigh Smith, Esq., to Spitzbergen, in 1873, was presented to the Trustees of the British Museum in the following year. The species are most of them well-known Arctic forms; but the specimens generally are of a large size and in an excellent state of preservation. The value of the collection is further enhanced by the exact locality of nearly every specimen being recorded.

The crustacean fauna of the Scandinavian and adjacent arctic seas appears to have been investigated more thoroughly than that of any other great region of the globe, if we may judge from the amount of literature relating to it; for in the Introduction to his 'Skandinaviske og Arktiske Amphipoder' (Christiania, 4to, 1872), A. Boeck enumerates no less than 273 publications in which animals of this order alone are referred to in connexion with this area.

In 1863 A. v. Goës published a list of the Decapoda inhabiting the region mentioned, with remarks on the geographical

distribution of each of the species (in Efvers. Kongl. Vetensk. Akad. Förhandl. p. 161); in addition to all which are mentioned below, he records many others from Spitzbergen.

The long-known and widely distributed Isopod Ega psora, Pennant (Ega emarginata, Leach), has not, to my knowledge, been obtained in these seas before.

In 1865 the Spitzbergen Amphipoda were dealt with by A. v. Goës (in Efvers. af K. Vet. Akad. Förh. 1865, pp. 517536, pls. 6). Anonyx bidenticulatus, S. Bate, is the only one in the present collection that is unnoticed by him. Mr. Spence Bate, in the Catalogue of Amphipodous Crustacea in the collection of the British Museum (1862), referred to this species as synonymous with A. nugax, Phipps; but a careful comparison of the two forms leads me to differ from him in opinion, and to consider them to be quite distinct from one another *.

The cirriped Balanus porcatus, Da Costa, is another addition to our knowledge of the Spitzbergen fauna; and so is one of the two species of Pycnogonida collected, Nymphon gracile, Leach.

DECAPODA.

HYAS, Leach.

Hyas araneus.

Cancer araneus, Linn. Syst. Nat. (ed. xii.) p. 1044 (1766); Pennant, Brit. Zool. iv. p. 6, pl. ix. fig. 16 (1777).

Cancer bufo, Herbst, Naturg. Krabben u. Krebse, i. p. 242, pl. xvii. fig. 95 (1790).

Hyas araneus, Leach, Ed. Encycl. vii. p. 431 (1814); Mal. Pod. Brit. pl. xxi. A. figs. 1-5; Bell, Brit. Crust. p. 31 (1853); Goës, Efv. Kongl. Vet. Akad. Förh. p. 161 (1863).

Hyas aranea, M.-Edw. Hist. Nat. Crust. i. p. 312 (1834).

Hab. Green Harbour (Ice Fiord), in 30 fathoms (Walker).

A single example (an adult male) is in the collection.

EUPAGURUS, Brandt.

Eupagurus pubescens.

Pugurus pubescens, Kröyer, Kongl. Danske Vidensk. Selsk. 7 Deel, p. 314 (1838); Nat. Tidsskr. förse R. ii. p. 251 (1838–9); Voy. en Scand.

* Among the shells collected were some miscellanea not seen by me, which were sent to the Rev. A. M. Norman for examination. Fragments of Vertumnus serratus, Fab., and of Byblis Gaimardi, Kröyer, were detected by him. Accepting his determinations, I include them in the list and give their synonymy. Their localities were not stated in the letter.