[53 J FLOUNDERS AND SOLES. 277 



Genus XXII.— ETROPUS. 



Etropus Jordan & Gilbert, Proc. U. S. Nat. Mus., 1881, 364. (Crossolus.) 



Type : Etropus crossotus Jordan & Gilbert. 



This genus is very close to Citharichthys, from which it differs only 

 in the very small size of the mouth, and in the correspondingly weak 

 dentition. The three known species are similar in appearance to the 

 species of Citharichthys, and they inhabit the same waters. Another 

 genus extremely close to Etropus and Citharichthys is Thysanopsetta. 

 The teeth in Thysanopsetta are, however, arranged in a band. 



ANALYSIS OF SPECIES OF ETROPUS. 



a. Body comparatively elongate, the head anteriorly acute ; dorsal rays 91 ; anal 

 rays 73 ; scales in the lateral line 54 ; back less elevated tbau in other species ; head 

 small, the profile forming an angle at the posterior part of upper eye, the snout 

 being abruptly pointed ; eyeslarge, 4£ in head, the lower being before the upper ; 

 interorbital space elevated, with two prominent ridges, the space between them 

 concave ; ridge above lower eye higher than upper and joining the latter behind 

 upper eye, to form a sharp ridge ; upper eye with some vertical range ; mouth 

 very small, the maxillary 4 in head, not reaching front of pupil ; teeth bluntish, 

 close-set, in one row, chiefly on the blind side ; scales and fins much as in E. 

 crossotus; the edge of the subopercle on the blind side fringed with white cirri, 

 as in the latter species ; scales large, loose, little ciliate ; gill-rakers very short 

 and slender ; gill membranes broadly united ; caudal fin rhombic, rather pointed ; 

 pectoral 1^ in head; fin rays scaly; head 5 in length; depth 2£; color light 

 olive-brown, with vague spots and darker markings; fins similarly marked. 



Ectenes, 60. 



aa. Body deeper, the head not acute in profile ; dorsal rays 76 to 85; anal 56 to 67 ; 

 scales 38 to 48 ; teeth sharp, close-set, uniserial. 

 b. Body somewhat elongate,' pear-shaped, the depth not more than half the length, 

 the body thinner and more compressed than in E. crossotus ; mouth very small, 

 the maxillary 4 J in head ; eye 3 to 3|- in head; interorbital space a narrow, sharp 

 ridge ; cirri on subopercle rather few and long ; D. 77 to 78 ; A. 57 to 61 ; lat. 1. 

 38 to 41. Head 4 in length ; depth 2£ to 2. Vertebras 9 + 25 = 34. Color gray- 

 ish, with a few irregular vague dark blotches, none of them larger than the eye ; 



fins speckled ; two dark spots at base of caudal Microstomus, 61. 



bb. Body very deep, the depth rather more than half the length ; eye 3| in head ; in- 

 terorbital space a narrow, sharp ridge, divided anteriorly ; maxillary about 4 in 

 head; head 4+ j depth 1* to 2 (1* in Atlantic specimens). D. 76 to 85; A. 56 to 

 67 ; lat. 1. 48 (42 to 45 in Atlantic specimens). Vertebrae 9 + 25 = 34 ; cirri on 

 subopercle of blind side numerous, white; color light olive-brown, with some 

 darker blotches ; vertical fins finely mottled and speckled with black and gray. 



Crossotus, 62. 



60. ETROPUS ECTENES. 



Etropus ectenes Jordan, sp. nov. 



Habitat. — Pacific coast of South America. 



The types of this species are two examples (11605, Mus. Conip. Zool.) 

 collected at Callao, Peru, by Dr. Jones. There are also a large number 

 of young examples in the collection (11145) obtained at Paraca Bay by 

 the Hassler Expedition. 



