i6^ FI.AITISHES (HETEROSOMATA) 



Tvpii. — United States National Museum. No. 43095. 

 Distribution. — Deep water off the coast of California. 



The type (about Qo mm.) was taken in the Gulf of California, north of La Paz 

 (i4 51' N., no' 39' W.), in 40 fathoms. 



Genus 19. MONOLEXE. 



M<')iol,n,\ Goode, iSSi, Proc. U.S. Nat. Mus., ill, (1880), p. 338 [Monolaic sesnticauJu. Goode) ; 



Jordan and Evermann, 189S, Bull. U.S. Nat. Mus., xlvii (3), p. 2b<),}. 

 ihyris, Cioode, 1881, lorn, cit., p. 344 [Thvrxs peUucidtts, (ioodcj. 

 Delolhyns, Goode, 18S4, Proc. U.S. Xat. Mus., vi (1883), p. 109 [Thyns fidluculic:. Goode]." 



Body ovate or rather elongate, much compressed. Eyes on the left .side, separated 

 by a ridge or very narrow space. Po.sterior nostril of blind side small, without mem- 

 branous valve ; olfactory laminae few, parallel to each other and to the main axis of 

 the body ; no central rachis. Mouth rather small, the length of the ma.xillary less 

 than J that of head ; jaws and dentition more or less equally developed on both sides ; 

 teeth minute, scarcely enlarged anteriorly ; uniserial in both jaws ; vomer toothless. 

 Ciill-rakers rather .short. Dor.sal Jin commencing above nostnls of blind side and well 

 in front of eye ; all the rays simple, more or less scaled on both sides. Tip of first 

 interhsemal spine not projecting in front of anal fin. Pectoral fin (in adults) developed 

 only on ocular side ; all the rays simple. Pelvic fins with bases of moderate length, 

 that of ocular side on median line, but scarcely in advance of that of blind side ; none 

 of the rays prolonged. Scales rather small, ctenoid on ocular side, cycloid on blind 

 side. Lateral line feebly developed on blind side : a strong cur\'e above the pectoral 

 fin ; no distinct supratemporal branch, \'ent on blind side, above first ray of anal 

 fin. Vertebra; 43. 



E'lve species from both coasts of tropical America. 



Synopsis of the Species. 

 L Depth about 2j in length ; eye 5* in head; dorsal 82, anal 63 . i dubiosa. 



H. Depth 2^ to 3j in length ; eye 2| to 3J in head. 

 A. Dorsal 96-106, anal 76-88. 



1. Depth nearly 3, head 5 in length . eye 3} in head ; 93 scales in lateral 



line ......... 2. ses'.ilicaiida. 



2. Depth 3 to 3!, head 4^ to 4J in length ; eye 3^ to 3^ in head ; 87 



to 88 .scales in lateral line ..... 3. aiiltllaiiiin. 



3. Depth il to 35, head 3! to 3I in length : eye 3J to 3? in head ; 104 



to 108 .scales in lateral line . . . . ■4- macidipinna. 



H. Dorsal 124, anal 100 ; eye z", in head .... 5 atrimana. 



I. .MONOLENE DUBIOSA, Garman. 



MimnUne iliibiosa, Garman, iXyo, Mtni. .Mus. Comp. Zool., xxiv, p. 227. 



Depth of body about 2^ in the length, length of head 3J. Upper profile of head 

 with a small notch in front of eye. Snout shorter than eye. diameter of which is 

 3* in length of head ; interorbital ridge low ; upper eye a little in advance of lower, 

 close to edge of head. Maxillary extending to below anterior part of eye. length about 

 4 in that of head ; lower jaw 3 in head. 83 scales m lateral line. Dorsal 82. Anal 

 03. Pectoral with 12 rays, length 2i in that of head. Caudal pointed (?) ; caudal 

 peduncle very short. Brownish ; edges of scales darker ; dorsal and anal fins brown, 

 with paler spots ; caudal pale with blackish dots , posterior half of pectoral black. 



' Substitute for I liyns (preoccupied). 



