i(.o l-LATFISHES (HETEROSOMATA) 



Jordan ami l''.vermann (l8q8) were unable to find any constant distnutit>iis betucen 

 examples of this variable species from the Atlantic and I'.n itu i im^i-, i. s|hc ti\. K oI 

 tropical America. Parr (1931) fonnd himself nnable to dillcrrnii.ii. ih. InlK jn.wn 

 specimens of the two regions, but noted that " there is ,1 1 unsnl'iMMr .iml ^i^mlii ant 

 ditterence in the ontogenetic development of the body width ". On the basis of this 

 chtterence he distinguished an Atlantic (atlanticus) and Pacific (crossotus) subspecies. 

 He further suggested the possibility of two separate forms still being confused in the 

 Pacific /;. ciossotus crossotiis, again distinguished by differences in body width at 

 certain stages of development. The type of E. crossotus, about 125 mm. in total 

 length, came from Mazatlan. On the Atlantic coast the species appears to grow to 

 about 140 mm. in length, and on the Pacific coast to more than 100 mm. 



(ienus 16. TKICHOPSETTA. 



Inchopsdla, C.ill, iSSr,, Proc. U.S. Xat. Mus., .si, (1SS8), p. 601 [CUharichthys venlrahs. (Inodc and 

 Bean] ; .lordan and Evermann, 189S, Bull. U.S. Nat. Mus., xlvii (3), p. 266.J. 



Hody ovate, much compressed. Eyes on the left side, separated by a narrow ridge, 

 with a median groove, at least anteriorly. Posterior nostril of blind side small, with- 

 out membranous valve ; olfactory laminae few, nearly parallel with each other and with 

 the main axis of the body ; no central rachis. Mouth of moderate size, the length of 

 the maxillary more than \ that of head ; jaws and dentition more or less equally 

 developed on both sides ; teeth very small, pointed, somewhat enlarged and curved 

 anteriorly, uniserial in both jaws ; vomer toothless. Gill-rakers rather long, slender. 

 Dorsal fin commencing above posterior nostril of blind side, and well in front of eye : 

 all the rays simple, more or less scaled on both sides. Tip of first interhaemal .spine not 

 projecting in front of anal fin. Pectoral fins unequal, that of blind side usually larger ; 

 all the rays simple. Pelvic fins short-based, that of ocular side with somewhat longer 

 base and placed on median line, that of blind side with the rays much prolonged. 

 Scales .small, ctenoid on ocular side, cycloid on blind side. Lateral line developed 

 only on ocular side of body, with a strong curve above the pectoml fin ; no supra- 

 temporal branch. Vent on blind side, above first ray of anal fin. 



.A single species from the Gulf of Mexico. 



I. TKICHOPSETTA VENTRALIS (Goodc and Bean). 



CWmrichlhvs vcntrahs, Goode and Bean, 1886, Proc. U.S. Nat. Mus., viii, (1SS5), p. y)2. 

 Arnnglossus (?) vcnlraln. Jordan and Goss, i88g, Rep. U.S. Com. Fisli., xiv, (1886), p. 2(>2. 

 Tnchopsella voilraUs, Gill, 1889, Proc. U.S. Xat. Mus.. .xi, (iSSS), p. (>oi ; Gonde and Bean, 1S95. 



Ocean. Ichth., p. 440, fig. 372 ; Jordan and Evermann, iSyS, Bull U.S. Nat. Mus., xlvu (3), 



p. 266Q, pi. ccclxxxiii, fig. 940. 



Depth of body 2 to 2J in the length, length of head 3* to 4. Upper profile of head 

 notched in front of eyes. Snout shorter than eye, diameter of which is about 4 m 

 length of head ; lower eye in advance of upper, which is separated from edge of 

 head by a space equal to about ^ its diameter. Maxillary extending to below middle 

 of eye, length 2^ to 1% in that of head ; lower jaw ij in head. 9 or 10 giU-rakers on 

 lower part of anterior arch, .\bout 65 scales in lateral line. Dorsal 91-94. Anal 

 71-74. Pectoral of ocular side with 12 or 13 rays, length about li in that of head ; 

 that of bUnd side with g rays, as long as or shorter than head. Caudal pointed : 

 caudal peduncle very short. Pale brownish ; some obscure dark markings at 

 junction of straight and curved portions of lateral line ; a dark blotch on anterior 

 rays of anal fin. 



Type. — United States National Museum. No 37343. 



Distribution. — Deep water in the Gulf of Mexico. 



