1854.] 135 



extending to the anterior rim of orbit. Eye circular : its diameter entering 

 four times in length of side of head. Origin of first dorsal opposite the middle 

 of base of pectorals, its base being nearly equal to that of anal and a little 

 shorter than that of second dorsal. Caudal forked. 



D X. I. 24. A III. 30. C. 3. 1. 6. 6. 1. 2. V I. 5. P 1. 21. 



The scales are subquadran^ular in shape, a little longer than high, provided 

 anteriorly with from five to seven grooves. 



Deep purplish brown above the lateral line, lighter beneath; sides of abdo- 

 men yellowish. Longitudinal light stripes between the rows of scales, more 

 conspicuous below than above the lateral line. Dorsals, anal, caudal and ven- 

 trals purplish, base of anal exhibiting a whitish stripe. Pectorals whitish or 

 yellowish. 



From San Francisco, Cal. 



15. Amphistichus similis, G. Among the specimens collected, there is one 

 a female a little over four inches and a half in length, which we propose to 

 describe as a very closely allied species to A. argenteus. There are two promi- 

 nent characters which will enable us to distinguish between both species : in A. 

 argenteus the posterior extremity of upper maxillary extends beyond to a 

 vertical line which would pass through the middle of the pupil, whilst in A. 

 similis it scarcely reaches the anterior rim of the same organ. Again, in the 

 former, the second and third spiny rays of the anal are much longer than in the 

 latter. The number of rays of fins is nearly the same; the anal has three and 

 the pectorals two more soft rays in A. argenteus than in A. similis. There are 

 also eleven spiny rays to the anterior dorsal of A. argenteus. 



D X. 24. A III. 25. C 2. 1. 6. 6. 1. 3. V I. 5. P 1. 24. 



The head is contained three times in the length, the caudal fin excluded. The 

 eye large and circular, enters less than four times in the length of side of head 

 by its diameter. The greatest depth is to the greatest length, as one to three. 

 The body is very much compressed. The insertion of ventrals is in a line with 

 the third spine of anterior dorsal, which is also the line of greatest depth. 



The coloration is not sufficiently preserved for comparative description. 



From San Francisco, Cal. 



16. Amphistichus heermanni, G. A specimen of this species, a little over 

 eight inches and a half in length, in affording one character proper to Holconotus 

 has left us for some time in doubt as to its generic affinities. We speak of the 

 structure of the dorsals, the anterior of which is composed of spiny rays higher 

 than the soft ones of the second. Indeed, there is a slight depression in the line 

 limiting these fins, corresponding to their point of junction ; but finding that such 

 was also the case in Holconotus, that character could no longer be of any 

 generic value. Seeing, however, that there were two rows of teeth on the lower 

 jaw as well as on the upper, and that the lips, rather thin, were not free upon 

 the symphysis of the lower jaw, we decided on placing it in the genus Amphis- 

 tichus where it really belongs. The shape and size of the mouth are altogether 

 similar to that observed in A. argenteus and A. similis. 



The body is very much compressed, of a short appearance, the nape promi- 

 nently arched, the head contained about four tim^s in the total length and the 

 greatest depth twice, the caudal fin excluded- Eye contained about four times 

 in the length of side of head. The posterior extremity of upper maxillary hardly 

 reaching the vertical of the anterior rim of pupil. 



The number of rays of the fins is the same as in A. argenteus, with an excep- 

 tion in the first dorsal, which has ten spines, instead of eleven, as in A. similis. 



DX. 24. A III. 28. C 3. 1. 6. 6. 1.3. V I. 5. P 1. 26. 



The color does not differ much from that of A. argenteus. 



From San Francisco, Cal. 



CIPRINIDJE. 



17. Gir.A conocepiiala, B. and G. There was but one specimen of this 

 species collected, about seven inches and a half in length. General shape sub- 

 fusiform, compressed ; back slightly convex from nape to posterior margin of 



