niger has the middle of the back nearly black; while that of M chrysosurus appears to be a variety, merely differing in the tail being more rufous" (l. c. p. 669). There is nothing in Pucheran's description of the last-named species to indicate it is not the young of S. hoffmanni. Judging from what I have seen in other species, the darker color of the lower surface in Alston's S. rufoniger as compared with S. deppei might result from immaturity; but in deference to Mr. Alston's opinion, grounded on excellent opportunities for deciding, I give the species provisional recognition. XVI. SCIURUS PUSILLUS, Geoffroy. Sciurus pusillus, "IS. GEOFFROY", DESMAREST, Dict. d'Hist. Nat. x, 1817, 109; Mam. 1822, 337, pl. lxxvii, fig. 2.-ALSTON, Proc. Zoöl. Soc. Lond. 1878, 670 pl. xli. Macroxus kuhli, GRAY, Ann. and Mag. Nat. Hist. 3d ser. xx, 1867, 433. NOTE. These names-the first with a query, the second unhesitat ingly-I referred in my monograph to S. astuans, influenced mainly by the strong aspect of immaturity presented by a specimen in the Museum of Comparative Zoology, which undoubtedly represents this species, notwithstanding the statement by Buffon, quoted by me, that the type of the species was shown by the sexual organs to be adult. Although Mr. Alston was unable to find the type of Geoffroy's S. pusillus, he seems to have established its distinctness from S. æstuans by finding two upper premolars in the British Museum specimens bearing that name. considers Gray's M. kuhli (which I treated also as the young of S. astuans) as unquestionably identical with S. pusillus. This is apparently a very rare species, as I have met with references to not more than half a dozen specimens in all. It is by far the smallest American species of Sciurus. He The subjoined summary indicates the changes in nomenclature here made from that adopted in "Monographs of North American Rodents", and also that employed by Mr. Alston in his recent paper "On the Squirrels of the Neotropical Region": INDEX TO VOL. IV. Abies 824 Agrotis campestris 175 eriensis 172 evanidalis 172 fishii 175 idahoensis 171 janualis 169 juncta 171 micronyx 171 mimallonis 175 opacifrons 170 pluralis 174 rosaria 172 Aira 829 Alburnops 419 missuriensis 403 Alencita 128 Algansea 419 Algonia 419 Alisma 825 Allen, J. A.: Description of a Fossil Passerine Bird Geographical Distribution of the Mam- malia 313 Synonymatic List of American Sciuri Allgewahr, L.: List of Coleoptera collected by 471 Allosomus 430 Alnus 121 Alopecurus 828 Alosa 428 æqualis 199 affinis 195 bellimanus 199 bispinosus 199 clamator 197 cylindricus 196 equidactylus 199 canadensis 112 Ridgway 219 hypsibatus 387 Antennarium 816 Anthaxia deleta 459 Antherophagus priscus 762 Anthus ludovicianus 557 spraguii 10 American Herodiones, Studies of, by R. Antiblemma canalis 185 Antilocapra americana 203 American Sciuri, Synonymatic List of the, Antispila 129 by J. A. Allen 877 Amia 414. Amiurus 414 natalis 405 Ammocœtes 413 Ammocrypta 438 Ammodromus maritimus 17 Amorpha 807 fruticosa 110 Antrostomus vociferns 613 Aphana rotundipennis 772 fossiger 382 malacerhinus 383 Aphodius aleutus 453 anthracinus 455 bidens 453 brevicollis 455 cribratus 455 cruentatus 456 marginatus 456 scabriceps 457 sparsus 458 |