131 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY—GENERAL REPORT. 
TracMnidae in the method, and we contemplated their insertion at page 38 of this report. 
When the first portion of our MSS. went to press, however, professional duties diverting our 
attention from this subject, a previous pagination brought this family at the present juncture, 
where we must now give it to the reader. 
We cannot help thinking that the natural affinities of the Batrachidae with the TracMnidae 
are more intimate than would appear at first s^ht, and we should not be surprised if further 
researches into their structure should favor their union into one single group, for Uranoscopus, 
or star-gazer, seems to establish a natural transition from the Batrachidae to the TracMnidae. 
It is anatomically related to the Tracliinids by the absence of the air bladder and the presence 
of pyloric appendages, whilst zoologically it reminds us of Batrachus and allied genera, by the 
shape of the head and body, the structure and gape of the mouth, and of the fins also: the 
position of the ventrals being the same in Trachinids and Batrachoids, inserted as they are in 
advance of the thoracic belt, and hence anteriorly to the base of the pectorals. 
Syn. — Batrachidae, Swains. Ess. class Fishes Amph. and Rept. II, 1839. 
The general aspect of the batrachoids is that of a large and depressed head followed by a 
body more or less tapering, sub-depressed anteriorly and compressed posteriorly, protected by 
ctenoid scales or entirely scaleless. The branchial apertures are continuous under the throat in 
Uranoscopus, and widely separated by an isthmus in Batrachus and in Porichthys. There are 
four branchial combs in Uranoscopus , and three only in Batrachus and Porichthys. The two 
latter want the sub-orbital hone, whilst the former possesses it largely developed. 
The carpus is very much developed, but all the carpal hones contribute to its development; 
besides, the pectorals fins, far from presenting a pediculated appearance, exhibit a broad and 
fan-like base. 
PORICHTHYS, Girard. 
Gen. Char. —Body elongated, thickish anteriorly, quite tapering posteriorly. Head smooth, large, and depressed. Eyes 
rather small. Mouth broad, moderately cleft, with its gape directed obliquely upwards. Lower jaw longest. Canine teeth 
upon the jaws, front of vomer, and along the palatine bones. Preopercle spinous. Branchial apertures large, extending below 
the insertion of pectorals, and separated by a wide isthmus. There are six branchiostegals rays on either side. Pectorals 
spear-shaped. Ventrals inserted in advance of the thoracic arch. Anterior dorsal fin rudimentary. Second dorsal and anal 
elongated, approximating to, but not united with, the caudal. Skin smooth and scaleless. Several series of mucous pores. 
Syn. — Porichthys, Grd. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 141. 
This genus differs from Batrachus by its dentition as well as by the numerous series of 
mucous pores which are observed over the head and body. Moreover, the head is smooth com¬ 
pared to Batrachus , since there are but few filiform tentacles instead of the membranous flaps 
which exist in the latter named genus. The branchial apertures are wider though the number 
of the gills is the same. 
PORICHTHYS NOTATUS, Grd. 
Plate XX Y. 
Spec. Char. —Upper surface of head quite flat. An acute preopercular spine stretching across the opercle. Posterior 
extremity of maxillar bone extending to a vertical line drawn posteriorly to the orbit. Four series of pores on either side of the 
body. A subgular and an abdominal series, as also several of these on the sides of the head. Upper regions dark bluish violet; 
sides and belly silvery grey. A sub-crescentic vitta beneath the eye. 
Syn. —Porichthys notatus, Grd. in Proc. Aead. Nat. Sc. Philad. VII, 1854, 141 and 151. 
