to occupy about half the height of the fin, each 

 consisting of a light ring - enclosing a much dark- 

 er space. At about the middle of the length. 

 these rings (in one specimen) become blended, 

 forming thence a black baud with a light line 

 above and below it which extends to the caudal. 

 The anal is dark browu, (black near the tail) with 

 a border almost white in its whole lengh. 



These notes of the coloring are taken from a 

 young specimen only twenty two inches long. — 

 In another, fifty two inches in length, the colors 

 though not essentially different were less brilliant. 



We find here grouped the arched head, the 

 month, the remarkable dentition, the branchial 

 aperture, the surface, the scales, the structure of 

 the fins, belonging to Anarrhicas. But they are 

 associated with an eel-like elongation of body and 

 a corresponding complete union of the vertical 

 fins, which must remove it from that genus. The 

 fish has in fact, at the first glance (excepting the 

 head) much the aspect of a Muraena. Its gener- 

 ic features may be thus stated. 



Anarrhichthys, Ayres. — Head smooth, arch- 

 ed, obtuse. Body very much elongated. Scales 

 small. Dorsal, anal, and caudal Jins united. — 

 Canine teeth in the front of the jaws; blunt, round- 

 ed teeth on the vomer and palatines and in the 

 lower jaw ; none on the superior maxillaries. No 

 ventral fins. 



A. ocellatus is apparently rare. Only two spe- 

 cimens have yet been seen, which by a singular 

 coincidence were brought into the market within 

 two days of the same time. None of the fisher- 

 men had seen the species previously. The stom- 

 ach ot the larger specimen contained fragments 

 of a Sea- Urchin, apparently a Cidaris, so that 

 their habits appear to be like those of the species 

 of Anarrhicas. Both specimens were taken in 

 the Bay of San Francisco. 



March 5, 1855. 



Dr. H. Gibbons in the chair. 



A valuable collection of fossil shells was pre- 

 sented in the name of Dr Antisell from Santa 

 Margarita. The thanks of the Academy were 

 voted for the donation. 



A letter from Mr. Philip B. Carpenter of 

 London, to the Rev. Mr. Cutler of this city, was 

 read, asking for authentic information or ex- 

 change of specimens in illustration of the Mol- 

 lusca of California. 



Dr. Wm. 0. Ayres presented specimens of the 

 following fishes — Ophiodon elongatus, Gir., Lcp- 

 tngunnellus gracilis, Ayres; Scorpacnulithys mar- 

 moratus, Girard; and Catostomus labiatus, Ayres. 

 with a description of the last mentioned species. 



Catostomus labiatus, — Ayres. 



Form elongated, fusiform, somewhat compress- 

 ed. Greatest depth, which is equal to the length 



of the head, contained in the total length not 

 quite six times. Dorsal outline gently arching 

 from the dorsal fin to the snout. Head subquad- 

 rangular in transverse section ; elongated in front 

 of the eye, so that the distance from the eye to 

 the border of the operculum on its own plane, is 

 contained nearly twice in the distance from the 

 eye to the tip of the snout. Length of the eye 

 about one fifth of the length of the head. 



Nostrils almost immediately anterior to the 

 eyes; the posterior aperture much the larger, 

 oval, covered by a large crescentic valve from its 

 anterior border. 



Mouth large and very protractile, the pedicels 

 of the intermaxillaries being long and the tissues 

 lax. Lips quite large and thick, papillose, the 

 papillae imperfectly arranged in rows ; the pos- 

 terior lip deeply lobed. 



Lateral line nearly straight, curving but slight- 

 ly downward near its origin. From its anterior 

 extremity two rows of tubes diverge ; one pas- 

 ses directly across, on the line separating the head 

 and body, till it meets the tube from the opposite 

 side ; the other passes forward, and quickly di- 

 vides into two branches, one running along the 

 supraorbital space and terminating at the nasal 

 cavity, and the other curving down and passing 

 along the suborbital bones in their whole length, 

 These rows of tubes are quite prominent. 



Scales largest on the posterior portion of the 

 body, quadrangular, longer than high, with nu- 

 merous radiating furrows. Sixty four scaler 

 along the course of the lateral iine. and eleven 

 above it in au oblique iine at the origin of the 

 dorsal fin. 



Dorsal fin, trapezoidal in form, arising at u 

 point equidistant from the snout and the base of 

 the caudal fin. Its length, which is a little less 

 than its height, is equal to the length of the head 

 anterior to the preopercular border. The fourth 

 ray, unbranched, is the highest, the first two be- 

 ing very short ; the last ray has a little more than 

 half the height of the fourth. 



The ventrals, rounded, arising posterior to the 

 middle of the dorsal, have a height not quite 

 equalling the length of that fin. 



The anal, somewhat acutely rounded, with a 

 height equal to the length of the head, is separa- 

 ted from the ventrals by a space nearly equal to 

 its own height. The fifth and sixth rays are 

 highest, the first very short. This fin overlaps 

 the caudal lor more than a third of its height. 



Pectorals rounded, their height equalling that 

 of the anal. 



Caudal concave, the central rays only a little 

 more than half as high as the external, which are 

 about equal to the anal. 



D. 3-12; V. 2-10; P. 17 ; A. 2-7: C. 18, with 

 six accessories. 



Color dark blackish brown above, becoming 

 lighter on the sides, and white beneath. 



