302 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. DESCRIPTIONS OF TWO SPECIES OF FISHKK COLLECTED BY PROF. A. DCOE!^ IIV CEIVTRAI, ITIEXICO. By TARLETO^ H. BEAN. The larger portion of the fishes presented to the United States National Mnseuin by Professor Duges in June, 1879, have been reported npon by Prof. D. S. Jordan in a previous paper of these Proceedings.* In all 8 species were transmitted by Professor Duges, 4 of them being described in the article just mentioned and 2 in the present paper as new to science. The discovery of Myxostoma and Amiurus in streams which flow into the Pacific is singular and interesting, and, at the same time, the occur-rence of additional genera, Zophendum and Hudsonius, characteristic of the Eastern United States, makes it desirable to know more of the climatic and statigraphic conditions existing in Guanajuato and adjoin-ing provinces. Ooodea and two of the Chirostomas are from a salt lake in the middle of a little volcanic plain in Valle de Santiago, Guanajuato. Myxostoma austiiiia Beau, sp. nov. The type specimens were collected at Piedad, ni Morelia (Michoacan), Mexico. They are numbered 23120 and 23121 in the United States l!^a-tional Museum catalogue. The species may belong to Minytrema rather than Myxostoma ; but in the absence of all the abdominal \dscera this point cannot now be settled. It has a remarkably small fontanelle. Descriptjon. — Body not elongate, rather stout. Lips j^licate, trun-cate or slightly rounded behind. The greatest height of the body equals about ^, and the least height of the tad -^ of the length of body.t The length of the head (.23-.24) is contained 4^ times in length of body. Its width (.15) equals the length of the base of the dorsal. The interorbital distance (.095) equals the length of the snout. The length of the operculum (.07-.075) equals h the length of the ventral. The long diameter of the eye (.04) is contained 6 times in the length of the side of the head. The distance of the dorsal from the snout (.45) equals 3 times the length of its base; the beginning of the dorsal is equally distant from the tip of the snout and the end of the anal. The longest dorsal ray (.16) is twice as long as the last (.08), and its length is contained 5 times in the distance of the anal from the snout. The length of the base of the anal (.085-.09) is contained twice in the distance from the snout to the nape. The longest anal ray (.22) equals in length the external caudal rays, measuring these from the origin of the middle caudal rays. The last ray of the anal is as long as the snout. The length of the middle caudal rays (.13) equals about J the height of the body. The distance of the pectoral from the snout (.25) is contained 4 times *Proc. U. S. Nat. Miis., vol. ii, p. 298. t Length of body is to be understood as length without the caudal.
BioStor
