much closer than that with Guatemala and the north, and that the boundary between the two sub-provinces is not found, as was supposed, in the depression of the isthmus occupied by the great lakes and their outlet the San Juan river, but must exist further towards, if not in, Honduras. Mr. Salvin says, "What I suspect to be the case, though I cannot as yet bring evidence to prove it, is, that the forests of Chontales spread uninterruptedly into Costa Rica, but that towards the north and north-west a decided break occurs, and that this break determines the range of the prevalent Costa Rican and Guatemalan forest forms."* I can confirm Mr. Salvin's supposition. The San Juan river forms no greater break in the forest than a dozen other rivers that run through it and fall into the Atlantic. But a decided interruption does occur to the north-west. It is found in the valleys of Humuya and Goascoran in Honduras, which, along with the central plain of Comayagua, constitute a great transverse valley running north and south from sea to sea, and cutting completely through the chain of the Cordilleras.† The highest point of this pass is 2850 feet above the sea, and the country around is composed of undulating savannahs and plains covered with grass. The Gulf of Honduras, cutting deeply into the continent, also plays an important part in preventing the intermingling of the faunas of the two sub-provinces, but the principal barrier is the termination of the great Atlantic forest north-westward, which even at Cape Gracias begins to give place to plains and savannahs next the coast.

*The Ibis, July 1872, p. 312.

+ Squier,States of Central America," p. 681.

Ch. XXI.]

INSECTS OF NICARAGUA.

379

My entomological collections were much more complete than my collections of birds, especially those of the butterflies and beetles. Mr. W. C. Hewitson has described 25 new species, but no list of the whole of the butterflies known from Nicaragua has yet been published. In Coleoptera I made large collections, but the extensive families of the Elateridæ, Lamellicorns, and others are still uncatalogued, and very many species remain to be described. The only beetles that have been catalogued as yet with sufficient completeness to warrant any general conclusions are the Longicorns. I collected about 300 different species, and Mr. H. W. Bates has enumerated 242 of these in a paper "On the Longicorn Coleoptera of Chontales, Nicaragua," published in the "Transactions of the Entomological Society for 1872." In an interesting summary of the results he gives the following analysis of the range of the species:

Omitting the peculiar species and those generally distributed in Tropical America, we have thus fortythree that are found in Chontales and in Mexico or the United States, and sixty-one that are found in Chontales and countries lying to the southward. The pre

ponderance of southern forms is not so great as in the birds, but when we reflect on the large number of peculiar species, and that the Longicorns of the Atlantic slope of Costa Rica are yet scarcely known, it appears likely that many of the Chontales species will be found ranging southward across the San Juan river, and that the Insect fauna will be shown to have the same relations as the Bird fauna; for, as the Atlantic forest continues unbroken much further southward than northward, so will the insects peculiar to the forest region have a greater range in that direction.

Mr. Hollick has beautifully drawn on wood a few of the characteristic Longicorns of Chontales, all of them, with one exception (Polyraphis Fabricii), being as yet only known from that province, but probably extending into Costa Rica.

One of these, the lovely little Cosmisoma Titania, No. 7 in Plate, has been appropriately named after the Queen of the Fairies by Mr. Bates. It was first found by Mr. Janson, junior, who came out to Chontales purposely to collect insects; and I afterwards obtained it in great numbers. The use of the curious brushes on the antennæ is not known. Another longicorn, about the same size (Coremia hirtipes), has its two hindmost legs greatly lengthened, and furnished with brushes: one I saw on a branch was flourishing these in the air, and I thought at first they were two black flies hovering over the branch, my attention being taken from the body of the beetle by the movement of the brushes.

Another fine longicorn, figured in Plate, Deliathis nivea, looks as if made of pure white porcelain spotted with black. It is a rare beetle, one or two specimens