Jordan and Evermann. Fishes of North America. 1493 



Suborder HOLCONOTI. 

 (THE SURF-FISHES.) 



We recognize the singular family of Embiotocidw as constituting a dis- 

 tinct group or suborder allied to the Percoidea on the one hand and to the 

 Pharyngognathi on the other, but without very close affinities with either. 

 The structures connected with the viviparous habit, the united pharyn- 

 geals, increased number of vertebra', double nostrils, perfect gills, and 

 many rays in the soft dorsal and anal, together with the unarmed bones of 

 the head, constitute the chief characters of the Holconoti. ( 0^x0$, groove ; 

 v&rog, back.) 



Family CLVII. EMBIOTOCID^E.* 



(THE SURF-FISHES.) 



Body ovate or oblong, compressed, covered with cycloid scales of mod- 

 erate size. Cheeks, operculum, and interoperculum scaly; lateral line 

 continuous, running high, without abrupt flexure, not extending on the 

 caudal fin; head rather short; mouth small, terminal; jaws with conical 

 or compressed teeth of moderate or small size, in 1 or 2 series; teeth 

 wanting in 1 genus (Neoditrema) ; no teeth on vomer or palatines; no 

 canines; lower pharyngeals united, without suture, their teeth conical or 

 paved; upper jaw freely protractile; lips full, the lower either forming a 

 free border to the jaw or else attached by a frenum at the symphysis; 

 maxillary short, without supplemental bone, slipping for most or all of its 

 length under the preorbital; opercular bones entire; branchiostegals 6 

 (or 5) ; gill rakers usually slender; gill openings wide, the membranes free 

 from the isthmus or very slightly connected; pseudobranclme present; 

 gills 4, a slit behind the fourth; nostrils round; the openings 2 on each 

 side; dorsal fin single, long, with 8 to 18 usually slender spines, which 

 are depressible in a groove; a sheath of scales along the base of the ante- 

 rior part of soft dorsal and posterior part of spinous dorsal; this sheath 

 separated by a furrow from the scales of the body; anal fin elongate 

 with 3 moderate or small spines and 15 to 35 slender soft rays, its form and 

 structure differing in the two sexes; ventral fins thoracic, I, 5; pectorals 

 moderate; caudal forked; oviduct opening behind the vent, the two 

 apertures always distinctly separated; air bladder large, simple; no 

 pyloric creca; vertebra 13 to 19-f-19 to 23 = 32 to 42. Viviparous. The 

 young are hatched within the body, where they remain closely packed in 

 a sac-like enlargement of the oviduct analogous to the uterus until born. 

 These foetal fishes bear at first little resemblance to the parent, being 

 closely compressed and having the vertical fins exceedingly elevated. At 

 birth they are from 1| to 2 inches in length, and similar to the adult 

 in appearance, but more compressed and red in color. Since the announce- 

 ment of their viviparous nature by Prof. Louis Agassiz, in 1853 and by 



* For an account of the genera and species of Embiotocidcn and a detailed description of 

 the development of Gymatogaster aggregates, see Eigenmann, 011 the Viviparous Fishes 

 of the Pacific Coast of North America, Bull. U. S. Fish Comm. 1892 (1894), 381-478. 



