190 



U. S p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



purple. The dorsal, caudal, and pectorals are dark greyish olive; the rays of the anal and 

 ventrals are olive, whilst their interdigital membrane is purple. 



A specimen, fourteen inches in total length, was caught in Toraales Bay, California, by E. 

 Samuels. 



Plate XL, fig. 1, represents Bhacochilus toxotes, somewhat reduced in size. 



Fig. 2 is a scale from the dorsal region. 



Fig. 3, a scale from the lateral line. 



Fig. 4, a scale from the abdominal region. 



List of specimens. 



HYSTEROCARPUS, Gibbons. 



Gen. Char. — Head is small or of medium size. Mouth small, gape slightly oblique ; jaws sub-equal. Lips rather thin ; lower 

 one free all round. Premaxillaries quite protractile. Teeth sub-conical, occupying the fore part of the jaws only, and disposed 

 upon one single row. Spinous portion of dorsal much longer and somewhat higher upon its middle than the soft portion. 

 Anterior articulated rays of anal simple, and preceded by three small spines. Caudal fm furcated. Branchiostegals, five on 

 either side. Scales large. Lateral lino concurrent with the dorsal outline. No scales upon the fins. Dorsal groove running 

 nearly along the entire base of the fin ; sheath formed of one row of scales only. 



SfN. — Hyslerocarpus, Gibbons, in Proc. Acad. Nat. Sc. Philad. Vll, 1854, 124. 



This genus bears a general resemblance to Aheona, Ennichthys, and Holconotus, by the outline 

 of its dorsal fin, the spinous portion of which is higher upon its middle than the highest articu- 

 lated rays. It differs, however, from them by that same spinous portion of the fin being much 

 more extended than the soft, which constitutes only a fraction of the entire base or length. 

 From Ennichthys and Holconotus it furthermore differs by the presence of one single row of teeth 

 upon the laws, instead of two. The base of the anal fin is also shorter. The anterior articu- 

 lated rays of the anal are simple, whilst they dichotomise in Aheona, Ennichthijs, and Holconotus. 

 Its afilnities with Abeona are apparently closer, since there is but one series of maxillary teeth ; 

 still the lower lip is free all round as is the case in Ennichthys and Holconotus, whilst it is 

 attached by a frenum to the symphysis of the jaw, as in Abeona. From the latter it may yet 

 be distinguished by a shorter caudal peduncle. 



HYSTEROCARPUS TRASKII, Gibbons. 

 PI.ATK XXVI, Fig. H. 



Spec CIhab.— Iti)dy sub-ulliplical in i\.» profile ; nape convex, frontal lino depressed. Eye circular, of medium size. Posterior 

 extremity of maxillary extending to a vortical line drawn in advance of the anterior rim of the orbit. In the male the upper 

 regions are dark or purplish brown, unicolor ; yellowish olive, spotted wilh black, on the lower portion of the sides ; throat and 

 belly yellowish golilin. In llie fimale tliu back is asli-colorcd, with irregular black patches, approximating somewhat to inter- 

 rupted bands, aiToss the sides ; belly lemon yellow. 



S\N.—Ifyslnocarpus Iraskii, GinnoNs, in Proc. Acad. Nat. Se. Philad. Vll, 1854, 105 & 124.— Grd. in Proc. Acad. Nat. 

 Sc. Philad. VIII, 18,10, 13G. 



