06 TELEOSTEI: llEMIBKANCHII. — XVIII. 



s.il nor ventral fins ; caudal small or wantin<T ; anal minute, of 1 or 

 2 ravs ; tail lon^. Male fishes with an egg-puueli, usually placed 

 on under side of tail and formed of two folds of skin which meet on 

 the median line. The eggs are received from the female into this 

 pouch, and retained for some time after hatching, when the pouch 

 opens and the young, then J to ^ inch long, escape. Genera about 

 14 ; species 150, in all warm seas. (o-i/V, together; ypddos, jaw.) 



a. Axis of head in a line with axis of body. (Stjnijnnlhiiue.) 



b. HunKTttl l)ones united below ; C. present; P. well developed; I), oppo- 

 site vent; shields not spinous SlPHoSTOJIA, Hl5. 



aa. Axis of head form in j; an aiif;le with axis of body; the head and neck 

 horse-shaped, or like that of a " Knight " at chess. (I/ippocamjnme.) 

 c. Body compressed ; occiput with a narrow, bon^' crest, surmounted 

 by a star-shaped coronet ; shields tubercular or f'i)inous ; egg-sac 

 in male at base of tail, which is prehensile and without tin. 



lliri'ocAMPUS, 106. 



105. SIPHOSTOMA Rafincsque. Pipe-fishes. {a'K^av, tube ; 

 (TToiia, mouth.) 



2.35. S. fuscum (Storcr). Commo.v Pipe-kisii. Top of head 

 sli<;htly keeled; D. covering 4 body rings and 5 behind vent; rings 

 18 to 20 -f- :J(i to 40; dorsal rays 'Mi to 40; snout moderate. Head 

 9; L. 7. Olivaceous, sides mottled. Newfoundland to Va., com- 

 mon. Numerous other species occur S. (Lat., dusky.) 



106. HIPPOCAMPUS Kafinesquc. Sea Houses. 



(These small fishes inhabit grassy bays and often the open sea 

 in warm regions. Tliey are wont to twist the very prehensile tail 

 around pieces of floating sea-weed or eel-grass. They are thus often 

 <lrifted to great ilistances in the sea. J he sj)ecies are very simi- 

 lar to each other, and not easily distinguished.) (Ancient uamu 

 from tTTTTof, horse, and »ca/x7rof, a wriggling creature.) 



2.36. H. hudsonius DeKay. Sea House. Dusky, unspotted, 

 but with grayish blotches, edged with blacki.sh; D. with <lark band; 

 snout 1 1 in head ; spines on head weak, with cirri ; spines all bliint- 

 ish. 1). 19, on .3^ of the 11 body rings. L. 6. Cajjc Cod to Fla., 

 not common. Several other species occur S. 



Order XVHI. IIE3I11JKANCU1I. (Tin: IIalf-gilled 

 Fishes.) 



Gills normal, but the branchihyals and pharyngeals reduced in 

 number; V. more or less abdominal. A small group of 5 or <i fam- 

 ilies, intermediatt; between the I.nphvbranchii and the true Acan- 

 Uioptcri. (t)(u-, half; (iiuiy^ia, gills.) 



