168 U. 8. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



which, in the present state of things, wo could but render more confused in attempting their 

 ulterior identification. 



EMBIOTOCA, Agass. 



Gen. Char. — Head of moderate development ; moutli small ; upper jaw slightly the longest. Lips thick and fleshy, lower 

 ono attached by a frenum to tlio symphysis of the dentary (chin). Prc-maxillaries protractile. Teeth on both jaws, short, 

 conical, blunt, slightly recurved and disposed upon ono single row. Pharyngeal teeth pavement like. Spinous portion f 

 dorsal fin generally lower than the soft; the greatest difi'ercnce in height between the two being observed upon tlicir contiguitv. 

 Five or S1.X branchiostegal rays. Scales of medium development; lateral line well marked, continuous from head to base I 

 caudal and concurrent with the dorsal outline. No scales upon the fins. 



SYH.—Emhiotoca, Agass. in Amer. Jour, of Sc. 2d series, XVI, 1853, 386 ; and, XVII, 1854, 3G6.— Gno. in Proc. Acad. 



Nat. Sc. Philad. VH, 1855, 320. 



There is another feature which exists more or less developed in the different species of this 

 genus ; we refer to an area of enlarged scales upon the post pectoro-ventral region. This 

 character is particularly evident in E. jacksoni, E. cassidii, and E. webhi. 



It is also proper to state that in two instances (E. ornata and E. cassidii) the youno', towards 

 the period of their escape, have exhibited a structure of the fins which reminds us forcibly of 

 what has been said to be the case in Rhacochilus toxotes ; the posterior extremity of both dorsal 

 and anal fins extending beyond the base of the caudal; the latter being long and truncated. 



1. EMBIOTOCA JACKSONI, Agass. 

 Plates XXVII & XXVIII, and Plate XXVI, Fias. 3 & 4. 



Spec. Char — General form sub-elliptical. Anal broadly rounded upon its external margin ; origin of that fin opposite the 

 sixth or seventh articulated ray of the dorsal. Tips of pectorals reaching a vertical line intersecting the base of the third 

 articulated ray of dorsal. Eyes rather of small than of medium development. Posterior extremity of maxillary reachinir a 

 vortical line passing in advance of anterior rim of orbit. Frontal region slightly depressed above the eyes. Branchiostegals 

 five in number. About sixty scales in lateral line. Female, uniform dark purplish brown ; male, olive brown with diffused 

 darker blotches. 



Stn. — Embioloca jacksoni, Agass. in Amer. Jour, of Sc. second series, XVI, 1853, 387 ; and, XVII, 1854,366. Gru. in 



Proc. Acad. Nat. Sc. Philad. VII, 1854, 151 ; and, VII, 1855, 320. 



As far as our own observations go, both males and females of this species reach about the 

 same size. From among a dozen specimens, two of them appear full grown. They are nearly 

 eleven inches in total length, and four in greatest depth. Tbey are those which we have caused 

 to be represented on the accompanying plates ; one being a female, the other a male. 



The head constitutes the fourth of the distance between the end of the snout and the tips of 

 the central rays of the caudal. Its upper surface is gently sloping from the occiput forwards, 

 with a slight depression above the eyes. The snout is sub-conical and rounded. The eyes 

 Bub-circular in shape, are under the medium size ; their horizontal diameter being comprised a 

 little more than four times in the length of the side of the head, measured as usually i'rom the 

 extremity of the snout to tlie extreme posterior margin of the opercle. The mouth is small, its 

 gape slightly oblique upwards, and the posterior extremity of the intermaxiHary extendin"- to a 

 vertical line intersecting the anterior rim of the orbit. There are from twelve to fourteen teeth 

 on the upper jaw, and from ten to twelve on the lower. They occupy the anterior portion of 

 the mouth. Four concentric rows of scales may be observed on the cheeks ; the row nearest to 



