426 DEEP-SEA FISHES OF THE ATLAXTIC BASIN. 



TLe total length of the specimen is 59 lines, of which the head makes 7, and the head 

 and trunk together 17. 



This species was picked up in mid-ocean in the South Atlantic, and was purchased by 

 the British Museum from the Godeflfroy Collection. 



Order HETEROSOMATA. 



Cranium posteriorly normal; anteriorly with twisted vertex, to allow two orbits on tlie 

 same side, or one vertical and one lateral; basis cranii not quite simple. Dorsal fin long, 

 of jointed rays. Superior pharyngeals 4, the third longest, much extended forward, the 

 inferior separate. (Cope.) 



Family PLEURONECTID^E. 



/ PhroneHi, Ratinesque, IntTico <1' Ittiologia Siciliana, 1810, It. 



riiiironcctid(r, Fleming, British Animals, 1828, 178. — Bonaparte, Catalogo Metodico dei Pesci Europei, 

 1846, 47.— SWAINSON, Nat. Hist. Fishes, etc., 1839, li, 187.— Gi'NTnER, Cat. Fish. Brit. Mus., iv, 399.— 

 Gii.L, Arr. Fam. Fish., 1872, 2, (No. 15).— Jordan and Gilbert, Bull, xvi, U. S. Nat. Mus., 813. 



Pleuronecteoidei, Bleeker, Tentamen, 1859, XV. 



Body strongly compressed, more or less oval or rhomboid, and with one of its sides 

 (which is upward when the animal is reclining on its side) colored, and the other (wliich is 

 downward) generally colorless; the scales are variously developed (sometimes ctenoid, 

 sometime.^ cycloid, and sometimes wanting) ; the lateral line is continuous behind; the Iiea<l 

 compressed, more or less rhomboid, and with the snout pointed; both eyes are on the same 

 side, one being on or near the forehead, the other comparatively low down; opercula 

 normal, unarmed, not concealed by skin; mouth terminal, and with an oblique lateral cleft and 

 ofi various extent; branchial apertures continuous below; brancliiostegal rays 5 to 8; dorsal 

 elongated, extending generally from about the rostral region to near the caudal fin; anal fin 

 also elongated, and extending- about as far back as the dorsal; both are composed almost 

 solely of articulated rays ; caudal fin distinct from the dorsal and anal; pectorals on both 

 sides; ventrals jugular. The skeleton has numerous vertebrse; pyloric caeca are generally 

 developed, but in small number. 



KEY TO THE SUBFAMILIES AND DEEP-SEA GENERA OP PLEURONECTID.fi. 

 (From Gill & Jordan, modified.) 



I. Mouth small; supramaxillary endiug before or under front of eye; teeth largest on blind side. 



rieuronectin(B 

 A. Teeth in one series. 



1. Teeth rather large, bluutisb or trenchant: eyes dextral (sometimes sinistral in one species); 

 ventrals (usually) both lateral. 



a. Dorsal fin with less than 80 rays; anal with less than 60. Eyes dextral. 



Lateral line not arched. Scales not imbricated, usually ctenoid in male, cycloid in female. 



Pleuronectes 

 Lateral line arched anteriorly. Scales ctenoid Limanda 



b. Dorsal fin with more than 95 rays; an.il with more than 80; body tmusnally elongate. 



Left side of skull with strong mucous cavities. Lateral line nearly .straight. An.al spine 

 present. Eyes dextral Glyptocei'IIalus 



Mucous cavities not present. Caudal subsessile; left pectoral only present; lateral line 

 present, arched on eyed side, straight on blind side. Eyes sinistral. 



Monolene 



II. Moutli large, supra niiixillaries end under eye; ventrals lateral; vomer ami jjalatiues toothless. 



Uipjtogloasina; 



A. Caudal fin lunate. 



1. Lateral line arched in front; scales cycloid IIipi-oglossus 



2. Lateral line not .arched. 



a. Teeth not arrow-sliapcd; gill-rakers few, short PLATY-soMATicmnvs 



B. Caudal fin not lunate, the middle rays produced. 



1. Later.al line arched in front; body usually sinistral. 



a. Dorsal fin single Paralicutiivs 



b. Dorsal in two parts, its anterior rays, as well as sinistral ventral, nnich prolonged. Scales 



ctenoid ; Notcskma 



2. Lateral line not arched. Body dextral IIlPFUGLOSSOlDES 



