100 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



caudal rays, its width being less than two-thirds of its height. Its height at the ventrals 

 is contained 8^ times in standard length; the least height of tail is half that of the body at 

 the ventrals. 



Cheek naked. Head length contained 4§ times in body length, its width about one- 

 third of its length. The intermaxillary is very short, extending to vertical from posterior 

 limb of anterior nostril. The maxillary is very strongly curved downward, and has a short 

 kujb at its anterior extremity, not visible without dissection. The maxillary extends back- 

 ward to a distance from the tip of the snout equal to the length of the head without the 

 snout. The peculiar arrangement of the teeth is described above in the generic diagnosis. 

 Most of those in the maxillary are inclined strongly forward. Gill rakers, 9 above the angle 

 and 13 or U l)elow. 



The long lower jaw, with the exception of the projecting tip, is included within the 

 upper jaw; its length is equal to the distance from the anterior nostril to the end of the 

 head. 



Eye circular, close to the profile, the interorbital area being very narrow. Its length 

 is equal to that of the snout, and contained 7 times in the length of the head. 



Dorsal tin inserted at a distance from the tij) of the sn(mt e(iual to 3 times the length 

 of the lower jaw, its base being as long as the head; the first ray is minute and about two- 

 thirds as long as the eye; the second ray is about two- thirds the length of the base of the 

 fin, and the subsequent rays rapidly and uniformly decrease in length to the last, which is 

 about twice as long as the first. All the rays except the first arc bifid. 



The aual fin is inserted under the second ray of the dorsal; its base is half as long again 

 as that of the dorsal, and nearly one-third as long as the body of the fish; its outline 

 resembles that of the dorsal, tliough slightly emarginate, its longest ray a little longer than 

 the longest of the dorsal, and half" as long as the base of the fin. All the rays except the 

 first are bifid. 



Caudal forked, its middle rays less than half as long as the outer rays, equal in length 

 to least height of caudal peduncle. 



Pectoral inserted under the tip of the opercular flap, its length equal to the greatest 

 height of the body. 



Ventral inserted at a distance fiom the snout equal to twice the length of the head, its 

 length slightly exceeding that of the pectoral, anil contained 7 times in the standard body 

 length. 



Radial fornrala: B. VII-IX; D. 1+11-12; A. 1 + 16-20; C. 17; P. 9-10; V. 5. 



Color blackish brown, the luminous pores inconspicuous, in a row in each side from the 

 pectoral region to the tail, and another below it from the throat to the origin of the anal. 



The Chnllcnfier obtained this form first from great depths near Bernuida, but subse- 

 quently at numerous localities in the Atlantic, Pacific, and Antarctic Oceans, at depths of 

 from 500 to 2,900 fathoms; and it has since also been obtained from very numerous local- 

 ities in the Atlantic by the Albatross and the Blale. Although many hundreds of 

 spwimcns are in the National Museum, the species is so exceedingly delicate and hard to 

 preserve that not one of them gives satisfactory op])ortunity for study. 



Neostoma qitadrioculatum, Vaillant, jd. viii, fig. 2, must be very similar to this species 

 (Exp. Sci. Trav. et Talisman, 99). 



According to Alcock, G, microdon has been found by the Investigator in the Bay of 

 Bengal, in 485 fathoms, and in the Andaman Sea, in 2G5 fathoms. 



CYCLOTHONE BATHYPHILA (Vaillant). (Figure 118.) 



Keostoma lathyphilnm, Vaillant, La Nature, 1884, 184 (name and rough figure only) ; Exp. Sci. Travailleur 

 et Talisman, 1888, 90, pi. viii, fig. 1, l.-i. 



Body elongate, compressed; its greatest height about one-eleventh of its total length; 

 the length of the head two-ninths. Vent midway between tip of snout and end of caudal 

 rays. Eye moderate; its diameter equal to half the length of the snout, and also to tiie 

 width of the interorbital sjjace; it is placed far forward, so that the length of snout is greatly 



