Rev. H. Clark on the Mexican Species of Hydropori. 173 XVIII. — On the Mexican Species of Hydropori. By the Rev. Hamlet Clark, M.A., F.L.S. A VERY interesting and valuable collection of Coleoptera, made by M. Truqiii during his residence of several years in Mexico, has recently passed into the hands of my friend Mr. Alexander Fry. The Dytiscidse of this collection I have, by Mr. Fry's kindness, carefully examined. Some of the species of the group are well known; but many others (and these especially the smaller species) appear to be new to science. The genus Hydro-porus especially (represented by sixteen species) presents no form that I am able to recognize as already described by Say, Melsheimer, or Leconte. Say's descriptions are somewhat im-perfect, and, in the absence of typical specimens, often insuffi-cient; and I have been unable to examine the fifth volume of the ' Annals of the Lyceum of Natural History of New York,' in which many of Leconte's species are described. With the aid, however, of the admirable analysis of the Hydropori of the States, drawn up by Dr. Leconte, and published in the ^ Pro-ceedings of the Academy of Natural Sciences,^ April 1855, and especially (in some cases) of type-specimens of interesting spe-cies described by him, which that gentleman has added to my cabinet, I have been able to satisfy myself of this, at least, that, whatever may be the characterized species of Mexican Hydro-poriy none of them are to be found among the species which I have been recently examining. I propose therefore in this paper briefly to describe the new species from Mr. Fry's cabinet and my own, having first enumerated those Mexican species of this genus that (so far as I know) are already determined. With the aid of Dr. Leconte (by his interesting set of types from his cabi-net, and also copies of valuable papers by him on North-American Coleoptera), and by the kindness of M. Bonvouloir of Paris (who has entrusted to me for comparison type-specimens of North-American species named by M. Aube), I believe that the list is tolerably accurate. The prefix to each species of a letter and figure indicates the subsection of the genus, as adopted in the following paper, to which the species may be referred. Species already described by authors : — (A. 1.) H. punctatuSy Say, Long's Second Exped. Philad. 1824, ii. 271. , Aube, Species General, 1838, 471. (A. 1.) H. cuspidatus, Germ. Faun. Ins. Eur. v. t. 4. Hyphydrus notatus, Say (?). (B. 2.) H. lacustris, Melsh. ; Say, Trans. Amer. Philos. Soc. 1823, ii. 103. H. pulicarius, Aube, Species General, 1838, 495.
BioStor
