178 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



The distance between the origin of the dorsal fin and the end of the snout is nearly 

 equal to that between the dorsal and caudal fins; its spines are very feeble, gradually in- 

 creasing in length behind, the second soft ray being the longest, but much shorter than the 

 base of the fin. The anal fin is small, with the spines very feeble ; and there arc not more than 

 two in the specimen from which this description is taken, while Mr. Lowe says that he has 

 found four spines in the first specimen which was discovered. The base of the. anal fin is 

 covered with rather large scales. Caudal fin small, forked, covered with scales at the base; 

 pectoral falciform, not quite as long as the head, and not extending on to the vent; ven- 

 trals much shorter, with the spine very feeble. The scales are large, especially on the 

 trunk, with the margin irregularly notched; they become smaller on the tail, but the tho- 

 racic region is covered with very large ones, especially one between the ventrals, being not 

 much smaller than the operculum. Lateral line none. Color, entirely black. (Giinther.) 



Eadial formula: D. VI, 11; A. II, 0; V. I, 7; lat. line 25; transverse line 7. 



Known only from Madeira. Lowe's type is said to be lost. 



PLECTROMUS, Gill. 



Plectromua, Gill, Proc. U. S. Nat. Mus. VI, 1883, 257, 258.— Bean. „p. cit., 1885, 73.— Jordan, Cat. Fish. N. A., 



1885, 74. 



Berycine fishes, resembling in form Melamphaes, with moderate cycloid scales. Head 

 large and thick, with wide muciferous channels, and often with conspicuous foliaceous con- 

 tinuations of the superficial bones. Cleft of mouth moderate, somewhat oblique. Jaws 

 nearly equal, though the under one is slightly the more prominent. Teeth villiform in the 

 jaws (in the type species, P. suborbitalis), arranged in two rows, of which those of the inner 

 row, at least in the lower jaw, are largest ; palatines toothless. A single dorsal, with 2 to 3 

 spines and 10 to 10" rays. Vent and origin of the anal under the last rays of the dorsal, 

 the anal fin with 1 spine and 8 to 9 rays. Ventrals thoracic, and with 7 rays as in Mel- 

 amphaes. Branchiostegals vni; pseudobranchiae present; opercles not armed. Caudal 

 forked. 



The genus Plectromus, which has been united with Melamphaes by European ichthy- 

 ologists, is provisionally maintained in this work on account of certain apparently valid 

 characters, such as the more normal position of the anal fin, which is inserted under the 

 end of the dorsal rather than far back as in the typical Melamphaes; also by the much 

 smaller number of spines in the dorsal and the larger number of rays in the anal, which 

 appears also to have 1 instead of 2 antecedent spines. 



Most of the Atlantic species described by Giinther appear to be more closely allied to 

 the Plectromus type than to Melamphaes typhlops, and arc provisionally placed in the genus 

 Pleestromus rather for the purpose of eliciting further discussion than as an expression of 

 positive opinion, for which the material at our disposal is not sufficient. Melamphaes eras- 

 sleeps, Giinther (of which a figure is given), appears, however, to be a very close ally of the 

 species described by Bean under the same specific name. 



In addition to the several Atlantic species, M. in yzolcpis, Giinther (Ann. and Mag. Nat. 

 Hist., 1878, II, 185, Chall. Beport, xxn, 28), obtained by the Challenger south of New Guinea 

 and off the Arroe Islands at 800 fathoms, and by the Investigator in the Bay of Bengal at 

 1,310 fathoms (Aleoch, Ann. and Mag. Nat. Hist., Sept., 1890, 201), seems to have affinities 

 with Plectromus. 



The following details concerning the genus Plectromus, as represented in the type 

 species, P. suborbitalis, are furnished by Dr. Gill: 



Body little compressed, highest behind ventrals, with the dorsal outline describing a 

 slight sigmoidal curve and the abdominal almost rectilinear; the caudal peduncle long and 

 robust. 



Scales moderate, imbricated, cycloid, and readily deciduous. 



Lateral line apparently undeveloped. 



Head oblong or longer than high, very declivous in front, and with the suspensorium 

 almost vertical; the cranium above with a naked skin extending from the nape forward to 



