PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 63 



Actual measurements of the parts are not given, as the proportions 

 vary but little. 



Several examples were collected November 20, 1879, at a depth of ten 

 fathoms, in Drake's Bay, 35 miles north of San Fiancisco, by Mr. Voy, 

 who has presented them to the State University, Berkeley, Cal. 



One of the types is in the United States National Museum, num- 

 bered . 



This species is referred to the genns Brachyopsis, proposed by Dr. 

 Gill for the reception of Agonus rostrafus. 



This genus is distinguished from Ayoniis by the projecting lower jaw 

 and consequent comparatively large terminal mouth, and by the absence 

 of an isthmus. 



DESt'RBPTION OF A IVEW OETVUS A1V» SOME IVEW SPECIES OF t'AIi- 

 IFORMA FISHES (ICOSTEUS .^EIVIGITIATICFS AIVO OSITIERUS AT- 



TEIVL'ATUS). 



By H^. N. I.OCKI]\GTOIV. 



Fam. BLENNID.^{?). 

 IC03TEUS. 



Body much compressed. Teeth in a single row in both jaws, close-set, 

 sharp. No teeth on vomer, palatines, or i)haryngeals. Gill-oiienings 

 continuous under the throat, composed of flexible rays, the anterior 

 simple. 



A single long dorsal fin; anal similar. Base of pectorals fleshy. Ven- 

 trals thoracic in position. Lateral line with groups of si^ines. Pseudo 

 branchiaj. 



Body scaleless throughout ; fins beset with spinules along the rays. 



Etymology: er/.u), to yield; o<T-£(r^, bone. 



Icosteus asnigmaticus. 



Body much compressed throughout; head thicker than any portion of 

 the body. Dorsal outline rising rapidly to the origin of the dorsal ; 

 thence more slowly in a regular curve to about the center of the length 

 of the bodj' ; thence curving gradually downward to the caudal pedunc^le. 

 Abdominal outline regularly curved. 



Upper and lower outlines of caudal peduncle concave, the peduncle 

 widening posteriorly to support the fin-shaped caudal. 



Greatest depth about 3A times in total length; length of head about 5 

 tiuies in total length ; eye G ; snout more than 3; interorbital width about 

 2i times in the length of the head ; caudal i)eduncle about 5| times in 

 the greatest depth. 



Nostrils simple, elongate-elliptical; eyes lateral, their diameter less 

 than the length of the snout ; mouth-opening ratlier large, horizontal, 

 or nearly so ; tip of the intermaxillary below the lower margin of the 

 eye ; margin of upper jaw formed of the intermaxillaries only ; maxilla- 



