DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 99 



physis of the lower jaw. On the palatines and possibly upon the pterygoids a few small, 

 sharp, pointed teeth. Oil I opening \ ery wide; the gill rakers long and thin. Preoperculum 

 rounded. Twelve short branchiostegals; ;it the base of each of the 8 anterior onesa lumi 

 qous dot. No pseudobranchia?. Gill laminae large. Probably the lower pharyngeal bones 

 covered with teeth similar to those in the jaws, bul in severalrows. The dorsal has its 

 origin nearly midway between the ventral and the anal, ami is composed of l."> or 1 I rays. 

 Adipose tin thread-like. Ventral in front of the middle of the body (no1 behii d, as stated 

 by Kner) with 7 rays, reaching to the vent. Anal with from 17 to 19 rays, beginning under 

 the last 3 or 4 rays of the dorsal, and the fin similar in heigh! to the dorsal. The cau- 

 dal is equal in length to that of the head from snout to preoperculum, and is strongly 

 forked. Pectoral small, pointed, and nearly as long as the caudal. The thin, caducous 

 scales with which the body is covered exhibit no radiating lines, simply delicate, concen- 

 tric rings. On either side two longitudinal rows of inconspicuous phosphorescent spots, 

 surrounded with black pigment; the lower row near the line of the belly begins near the 

 throat and ends at the origin of the anal. In the space from the pectoral to the ventral are 

 16 spots; between the ventral and the anal 11; the upper row commences with 2 large 

 spots upon the suboperculum, and continues back to the caudal. Color, dark gray; the back 

 and belly silvery; all the fins whitish, uniform color. 



Eadial formula: D. 13-14; A. 17-19; V. 7. 



'flu's form, described in 1870 by Kner from a single badly damaged specimen taken in 

 the. Atlantic, is evidently a true Gonostoma. It closely resembles in many respects Mauro- 

 liens Poweriee and Maurolicus attenuatus of authors, which seem to have little affinity with 

 the typical species of Maurolicus. 



We have before us a specimen taken by the Blake from Station ccxlv, off Havana, at a 

 depth of 243 fathoms. Other specimens were taken by the Blake from Station xliii, off 

 Grenada, at a depth of 461 fathoms; from Station xxrv, off Grenada, atadepth ofl61 fath- 

 oms; from Station xly, in the old Bahama Channel, at a depth of 500 fathoms, and from 

 Station xi/VT, off Bequia, at a depth of 458 fathoms. 



CYCLOTHONE, Goode and Bean. 



Cyclothone, Goode and Beax, Hull. Mus. Comp. Zool., 1883,221 (type, Cyclothone Ui8ca=Gono8toma miorodon, 



GDnther). 

 Xeosloma, Vaii.lant, Exp. Scient. Travailloni et Talisman, 1888, 86 (1ypc, A. bafliiijihilum). 



Body elongate, somewhat compressed, apparently devoid of scales;* lower parts with 

 inconspicuous series of luminous spots, with the latter arranged approximately as in Gono- 

 stoma, but usually much less conspicuous. Head conical, compressed ; cleft of mouth very 

 wide, oblique, extending behind the eye. The lower jaw strongly projecting. Maxillary 

 long and slender, sickle-shaped; somewhat dilated posteriorly, but covering only an incon- 

 siderable portion of the cheek. Upper jaw with a single series of needle-like teeth, some 

 of which are enlarged; lower jaw with similar teeth, and in some species with a few canines 

 in front. Teeth on vomer sometimes in patches, sometimes reduced to a single pair of 

 fangs. Palatine and pterygoid teeth present or absent. Eye moderate, not conspicuous. 

 Gill opening very wide, the membranes free from isthmus. Gill rakers numerous, long and 

 slender. Pseudobranchia? none. Branchiostegals. No air bladder. Dorsal and anal 

 moderate, opposite, the latter much the longer. Adipose fin sometimes present. 



CYCLOTHONE MICRODON, (GOnther), Goode am. Bean. (Figure 114.) 



Gonostoma microdot!, GOnther, Ann. anil Mag. Nat. Hist., 1S78, n, 188: Voy. Chall., XXII, 175. — Alcock, 



Bathyhial Fishes of the Bay of Bengal, 1869, 25. 

 Cyclothone lusca, GOODE and Beak, Bull. Mns. Comp. Zool.. x. 1883, 221.— JORDAN, Cat. Pish. X. Am., 46. 



Body elongate, its greatest height contained 7jj times in its length to base of middle 



* It is possible tliat very thin ami exceedingly caducous scales may 1"' present in lit'-, but they are so 

 exceedingly loosely attached that not a single one has bei n found upon hundreds of individuals examined 

 by ns. ami at all events tln-y an- very different from the more persistent scales of Go Atnudatum. 



