4 PROCEEDINGS OF THE ACADEMY OF 



Pectoral fins suboval, directed downwards and inwards, and externally con- 

 cave. 



Ventrals situated nearly midway between the pectoral and dorsal. 



Prof. Jeffries Wyman has published interesting facts respecting the embryo- 

 logy of the Anableps Gronovii of Valenciennes (or Anableps tetrophtkalmus Linn.) 

 in the fifth volume of the Proceedings of the Boston Society of Natural History, 

 page 80, and in the sixth volume of the American Journal of Science and Art. 



Mr. J. P. G. Smith has published observations on the habits of a species of 

 the genus in the Proceedings of the Zoological Society, for 1850, at page 53. 



Anableps Dowei Gill. 



The body is elongated, anteriorly depressed and flattened, and posteriorly 

 compressed as in the other species of the genus. The height of the trunk, at 

 the insertion of the ventral fins is nearly an eighth of the extreme length from 

 the snout to the margin of the caudal fin. The width is greatest between the pec- 

 torals and ventrals, and equals fourteen-hundredths of the length ; thence it 

 nearly uniformly diminishes towards the base of the caudal fin, which is much 

 compressed. 



The head is elongated, semiconical in profile, above straight and continuous 

 with the back. The height at the vertical of the operculum equals an eleventh 

 of the total length. The length of the head itself enters five times in the total. 

 The head above is flat and level from the nape, and between the raised orbits 

 to the upper jaw ; its breadth at the nape slightly exceeds two-thirds of its 

 length ; that before the eyes equal three-fifths of the same. 



The eyes exceed in their diameter one-fifth of the length of the head ; they 

 are distant from the anterior borders of the nasals, a quarter of the head's length: 

 the interorbital space equals a seventh of the same. The interval between the 

 upper jaw and the angle of the preoperculum equals three fourths of that 

 between the jaw and the margin of the operculum. 



The eyes are circular; the portion below the bridle of the conjunctiva is 

 as large or larger than that above. 



The dorsal fin commences between the posterior sixth and seventh 

 tenths of the length. Its basal length is only equal to a twentieth of the total 

 length, and scarcely exceeds half its height. Its median rays are highest, the 

 margin being convex. 



The anal fin of the male has nearly the same position and structure, as that 

 of the same sex in Anableps tetrophtkalmus. 



The caudal fin is somewhat obliquely truncated, the lower rays being slightly 

 longest. Its greatest length farms a sixth of the total. Its basal third is 

 covered with closely adherent scales. 



The pectoral fins do not quite equal in length a seventh of the total; they 

 are separated from each other at their bases by an interval slightly exceeding 

 half their length. 



The ventrals commence between the fourth and fifth tenth of the total length; 

 their length equals a tenth of the same. 



In structure and form, the various fins do not differ from those of the allied 

 species. 



1 

 The number of rays is as follows : D. 8. C. 5, 16, 3. R. 21. V. 6. 



1 



From the axilla of the pectoral fin to the base of the caudal, there are about 

 sixty-eight rows of scales, forty-nine of which are in advance of the dorsal. 

 Each scale is more or less subcircular, often higher than long, with concentric 

 striaj, surrounding a nucleus placed considerably anterior to the centre, and 

 posteriorly crossed by about fourteen radiating striae. 



The color is a dark black brown on the head, back and sides. A broad, 

 longitudinal, golden-colored band traverses the sides and terminates at the 



[[Jan, 



