18G 



U S. p. E R. EXP. AND SURVEYS — ZOOLOGY — GENEEAl. REPORT. 



List of specimens. 



ABEONA, Girard. 



Gf.n. Char. — lload of medium size ; mouth very small ; jaws equal. Li]is raUier lliin ; lower one attached by a frcnuni to 

 the symphysis of tlie jaw. Premaxillaries protraclile. Teeth stoutish, conical, disposed upon one bingle row on both jaws. 

 Brancliioslegals five fn number. Spinous portion of dorsal fin higher than the soft ; line of separation between both of these 

 slightly depressed. Articulated rays of anal all dichotomised ; spiny rays, three in numlier.well developed ; base of that fin rather 

 short. Scales of moderate size. Lateral line concurrent with the dorsal outline. No scales upon the fins. Dorsal groove 

 extending nearly to the whole base of the fin. Sheath formed by two rows of scales. 

 Siii.—Abcona, Grd. in Pruc. Acad. Nat. Sc. Pliilad. VII, 1855, 322. 



With the general facies of Amphistichus, this genus differs from the latter by a much smaller 

 moutli and one row of teeth on the jaws instead of two. Also, by the spinous portion of the dorsal 

 fin, which is higher than the soft portion instead of being lower. The anal, likewise, is much 

 shorter and proportionally deeper. From Holconotus it differs by the lower lip, which is 

 attached to the chin instead of being free all round, by the presence of a single row of teeth on 

 the jaws, by a smaller mouth, by a shorter and deeper anal fin provided with more developed 

 spiny rays. From Emhiotoca, which it most resembles, it is to be distinguished by the spinous 

 portion of the dorsal -which is higher tlian the soft, more developed anal spines, and by the 

 uniformity of all the articulated rays of the latter fin. The teeth are proportionally larger, as 

 are likewise the scales. 



ABEONA TROWBKIDGII, Q r d . 



Platk XXXIV, Figs. 6—10. 



Si'Ec. CiiAR. — General form sub-elliptical. Head sub-conical; snout abbreviated; mouth small; posterior extremity of 

 maxillary not reaching the vertical of anterior rim of orbit. Eyes large, circular. Bramhiostegals five on either side. Forly-ono 

 scales in lateral line. Olive or reddish brown ai ove ; silvery on the sices and abdomen. Flanks blotched. Fins yellowish, 

 except anal, which is purplish, with its anterior portion spotted. 



SvN. — Hokonidva Irow'jridgii, Gud. in I'roc. Acad. Nat. Sc. riiilnd. VII, 1854, 152. 

 Mcuna hvwbrUlsh, Grd. in I'roc. Acad. Nat. Sc. I'hilad. VII, 1S55, 322. 



The body has a rather short appearance, being sub-elliptical in shape and not unlike a small 

 Pomolis. Its greatest depth is greater than the third of tlie entire length, in which the liead 

 enters a little over four times. The snout is rather obtuse, terminated by a small mouth, the 

 angles of which not extending to the vertical line intersecting the anterior rim of the orbit. 

 The lips are thin, the lower one being attached by a frenum to the symphysis of the jaw. The 

 teeth are proi)ortionally large, stoutish, and sub-acute. The nostrils are situated towards the 

 upper surface of the snout, nearer to the orbit than the extremity of the latter. The eye is 

 very large, circular in shape, and its diameter contained a little over three times only in tlie 

 length of the side of the head, and less than once in advance of the orbit. The scales upon the 



