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U. S, P. K. R, EXP. AND SURVEYS-ZOOLOGY—GENERAL REPORT. 
(Gyclopterus), exhibit traits of a kindred nature. In most of the minnows ( Cyprinodontidae ) 
and the Anableps, the eggs hatch within the abdomen of the female, and in the Embiotocoids 
there is a special pouch within which the eggs are first formed and afterwards develop until the 
young have undergone their fullest metamorphoses. The Embiotocoids, when observed for the 
first time, seemingly recalled to mind the opossum of North America, and the entire tribe of 
the kangaroo of Australia ; hut if any fish deserves the appellation of opossum-fish we venture, 
to claim it for the tribes of LophobrancMi we are treating of in these pages. 
The LophobrancMi have been recently the subject of investigations on the part of Mr. Kaup. 
The genera which he has established being for the present known to us only nominatively, we 
are at a loss to distribute them in the families we are inclined to adopt in the present Order. 
The generic divisions adopted by Mr. Dumeril in his “ Ichthyologie analytique” are not 
sufficiently characterised to the same purpose. 
Family HIPPOCAMPIDAE, Owen. 
The 11 sea-horse” family being composed, to our knowledge, of hut one genus ( Hippocampus ), 
we will not enlarge upon its characters here, since alluding to them would he a mere repetition 
of their enumeration further on. 
Syn. — Ilippocampidae, Owen, Lect. Comp. Anat. Vertebr. Anim. 1846, 50 .—Bd. Iconogr. Encycl. II, 1850, 232. 
This family is not adopted by all systematic writers, some of whom combining it with that of 
Syngnathidae, either under the latter appellation, else designating it by the name of the Order 
itself. The position these fishes assume in the media in which they live is not the least of their 
peculiarities entitling them to the rank of a family in the ichthyic method. 
HIPPOCAMPUS, Cuv. 
Gen. Char. —Body short, deep, and compressed heptangular ; tail slender, quadrangular, tapering, and coiled up inwardly. 
External surface of both body and tail divided into parallelograms by longitudinal and transverse ridges, with tubercular points 
at the angles of intersection. Head sub-pyramidal, bent downwards. One dorsal fin ; neither caudal nor ventrals ; an anal 
fin in noth sexes. Pectoral fins of moderate development. 
Syn. — Hyppocampus, Cov. Regn. Anim. II, 1817, 157 ; 2d ed. II, 1829 ; &, ed. illustr. Poiss. 331.— Storer, Rep. Fish. 
Mass. 1839, 167 ; &, Synops. 1846, 239.— DeKay, New Y. Faun. IV, 1842, 322.— Dum. Ichthyol. analyt. 
1856, 170. 
Deprived of caudal fin to execute their onwards motion, the sea-horses (Hippocampus) are 
reduced to coiling up their tail and to assume a vertical position in the medium in which they 
live, a position unknown elsewhere in the class of fish. They progress slowly and uniformly 
forwards or obliquely upwards ; in their descending movements the orientation is not changed; 
the tail remains directed downwards. The movements are executed by the means of the pec¬ 
toral fins ; the dorsal acting chiefly as a rudder. They appear to be easily tired, for after 
being active a short time they seek submarine supports to which they attach themselves by the 
means of their prehensile tail. 
HIPPOCAMPUS INGENS, Grd. 
The Great California Sea=IIorse. 
Spec. Char.—B ody composed of twelve segments ; tail longo- than the body and head together, divided into thirty-eight 
segments. Head constituting the sixth of the total length ; it being contained about twice in the length of the body and thrice in 
that of the tail. Spiny crest at the base of the snout rather inconspicuous. Three pairs only of thoracic bony processes. Blackish 
or deep chesnut brown, punctulated with white. 
