172 THE VOYAGE OF H.M.S. CHALLENGER. 



5. A scries of five on each side of the abdomen, somewhat above the lower profile. 



6. A series of seventeen along each side of the lower profile of the tail ; these are 

 smaller than the preceding, and the series is slightly interrupted behind the anal fin. 



7. The oro-ans on the head are all placed in its lower half; a series of six occupies the 

 roots of the branchiostegals. 



8. A very large one is placed above the lower rim of the prseoperculum. 



9. A small one occupies the suboperculum where it joins the operculum. 



10. Finally, two of the smallest are placed, one in front of, the other behind the eye. 



Gonostoma, Eafin.' 



As far as it is possible to make out the anatomical structure from a specimen of 

 Gonostoma denudatum which has been preserved in spirits for some time, the conditions 

 are the following : — 



The cesopliagus is continued into a very long, tapering caecal stomach, the pyloric 

 portion of which is surrounded by seven short pyloric appendages. The intestine is 

 narrow throughout, attached in its upper portion along the csecal sac of the stomach, and 

 continued in a straight line to the vent. 



The air-bladder is not only present but of large size, extending from one end of the 

 abdomen to the other. Its dorsal wall, as well as its posterior extremity, is rather 

 thick, whilst the membrane on its ventral aspect is very thin. I am unable to find any 

 communication between it and the oesophagus. A narrow muscular band starts from 

 each side of its anterior third, and is attached to the intermuscular ligaments of the fore 

 part of the trunk. The posterior end of the bladder is obtusely rounded, and has a 

 conical, muscular body attached to its ventral side. This muscular body is hollow in its 

 interior, and seems to communicate with the cavity of the bladder ; the broad end of the 

 cone rests upon the coalescent mass of the kidneys, and is suspended by a tendinous 

 ligament from the vertebral column. . 



Ovaries large, elongate, lamellated ; ova minute. 



Gonostoma denudatum, Raf. 



D. 14-15. A. 30-31. P. 11-12. V. 8. L. lat. 36. 



The height of the body is contained five and a half times in the total length (without 

 caudal), the length of the head four times. Jaws heterodont, the intermaxillary being 



' A fisli, mentidiicd under tlie name of Sigmops stigmaticus (Proc. U.S. Nat. Miis., 1884, p. 256), is not recognisable 

 from tlip notes acconijmnyinf:; this binomial term. 



A fish, mentioned and rudely figured in La Naliire, 1884, ]i. 1S4, under the name of Neostoma bathyphillum 

 [1 hathjphilum], L. Vaill., from a depth of 2220 metres in the Eastern Atlantic, seems to belong to Gonostoma. 



