40 DEEP-SEA P^ISHES OF THE ATLANTIC BASIN. 



tojiother, the anterior near tlic middle of tlic leiigtli of the snout. Eye large; its diameter 

 three-eleveiitiis()rtiielciij;thotthe head; iiiterorbital space two-elevenths. Gill oi)euing\vide; 

 operculum for the most part membranaceous, its elements being very imperfectly ossitied; 

 preopercnhim curved, thickened on its anterior edge; the interopercnlum and suboperculnm 

 not ])roininent, and apparently rejjhiced in i)art by the branchiostegals. Gill rakers, about 

 15 below angle. 



The vent is a little behind the middle of the total length. Lateral line extending from 

 the upper part of the branchial opening to the middle line of the body. Scales remarkably 

 small; those of lateral line very simple and more than a liundred in number. 



Dorsal with its outline a little convex, lower behind and ending at a distance from the 

 caudal ecpial to the length of its own base, which is equal to about one-eighth of the length of 

 the body; anal more than twice as long, beginning near the vent ami terminating a little 

 behind the- dorsal. Its height nearly the same as that of the dorsal. Caudal moderately long ; 

 its length equal to one-seventh of the length of the body, slightly emarginate ; pectoral small ; 

 ventrals very short. 



Color reddish brown; head a beautiful azure-blue; tins sepia; iris black; pupil azure-blue. 



Scales very simple in form; those of the body are rounded in outline and measure from 

 l.") to 1.0 mm., in diameter. Five pyloric cneca, moderately elongated. No trace of a swim 

 bladder. 



Radial formula: B. 0; D. 21; A. 4(t; V. 8; V. .5. 



Sixteen specimens of tliis species were obtained by the French expedition from the 

 coast of Morocco to Soudan, from the Banc d'Arguin, and from the Canaries, at depths 

 varying from 865 to 2,115 meters. A specimen 8 inches in length was obtained by the Alha- 

 tross at station 2751, hit. 10° 57' N., Ion. 03° 12' W., in OS fathoms. 



BATHYTROCTES, Gunther. 



Balhytroctes, Gunther, Ann. and Mag. Nat. Hist., ii, 1878, 2i'J; Cliallcnger Report, xxii, 225; Study of 

 Fislies, 6ftl. 



Body rather elongate, compressed, covered with scales of moderate size. Cleft of the 

 mouth rather wide, the maxillary extending to below the middle of the eye. Both in- 

 termaxillary and maxillary armed with a series of minute teeth, as is also the mandible; 

 palatine bones with similar teeth; those on the latter often weak and deciduous. Vomer- 

 ine teeth j)resent or absent. No teeth on the tongue. Eye very large. Dorsal and anal 

 flus moderately long, the former behind the ventrals. Adii^ose fin none. Caudal forked. 

 Gills very narrow ; pseudobranchia' present; gill rakers long, lanceolate. Pyloric a))pend- 

 ages in moderate number. Ova rather small. 



Bathj/trdctrs is closely allied to Alcpnrcphalns, from which it differs chietly in the pres- 

 ence of teeth on the maxillary. Ten species have been described, seven of which are from the 

 Atlantic. One of these, B. attritm. is, by the admission of its describer, quite as likely to 

 belong to some other genus — pei'hai)s Alrpocephahis. 



The type of this genus is Bathytroctcs mncrolcpis, Giinther, I'rom a dejjth of 2,150 fath- 

 oms, north of Celebes {Ghallenger station xcviii). — B. squamosus, Alcock is from 740 fathoms 

 in the Arabian Sea. B. .stoviias, Gilbert, is from 877 fathoms, off Oregon and Washington. 



KEY TO 'I'lIE SPECIES OF BATHYTROCTES. 



I. Dorsal fin far in .advance of tlie anal Batiiytroctks 



A. Anal insorted nearly lielow raiddli^ of dorsal. JlaxiUary reauhiug to below [KKsterior third of orldt. , 



1. Scales large (42 in lat. line). Vertical fins short. (D. 1,5; A. 11.) 



[BATnYTROCTES MACRDLKPIS] 



2. .Se.'ilos niodcrale (.")7 in l.it. line) Vertical fins moderate. (D. 17; A. 11). Month very large. 



[li. STO.MIAS] 



3. Scales small (100 J in lat. line). Vertical tins moderate. (U. 20: A. 17.) B. kOstkatus 



