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



Passing to the lower side of the head, we find the space between the mandibulaiy 

 rami occupied only by elastic skin, which, when the rami are closely approximated to 

 each other, projects as a broad fold on the inside of the gape; it is more or less wrinkled 

 on its inner surface, especially posteriorly, where it passes into the pharynx. Its 

 inner membrane, backwards to the end of the stomach, is deep black like the outside. 

 There is no tongue; if any rudiments of hyoid elements exist, they would be displaced 

 together with the branchial apparatus a long way behind the head. 



The " small, sharp, delicate teeth " which Johnson saw in his specimen were rather 

 loosely attached to the jaw-bones, and have now almost entirely disappeared; and if we 

 had not his testimony, confiimed by the dentition of another example, the dentition in 

 the present condition of the specimen might have been described as " granulations " in 

 the upper jaw, and as almost absent in the lower. The dentition has been restored in 

 the figure from the remaining teeth or traces of teeth in the specimen figured, with the 

 aid of the perfect dentition in our young specimen. 



The smaller example in the British Museum shows that the teeth are very 

 slender, of two sizes, the longest strongly curved, with the point directed towards the 

 inside of the mouth; the largest is 2^ mm. long; the majority are 2 mm., and the smaller 

 sized ones only 1 mm. long. Those of the lower jaw are generally smaller than those 

 of the upper, and so much dii-ected inwards as to be entirely hidden by the fold of the 

 skin which covers the inside of the jaws. The largest teeth, from ten to twelve in 

 number in each jaw, are widely set and placed in the same line ; the interspaces 

 between them are occupied by the smaller teeth, which may be inserted also in the 

 same line, or somewhat external to it. 



This dentition is much too feeble to be capable of injuring or holding any of 

 those large and powerful fishes which, as we know, are attacked by the species of 

 Saccopharynx, therefore they cannot afford the same amount of assistance in over- 

 powering the prey as the dentition of Omosudis and others, or even of Chiasmodiis. 

 But they are sufficiently strong to enable the Saccopharynx to fasten itself to and 

 retain its hold on another fish, which may drag its enemy a long way before its 

 strength is played out, and before the Saccaphai'ynx commences to di'aw itself over 

 its victim similarly to an Actinia which has captured a large fish or crab. There is 

 not the slightest reason for supposing that the mode of feeding differs in any of the 

 species of this genus. And so far from its being " probable that they may derive their 

 food from the water which is received into the poutli, by a process of selection of the 

 small or minute organisms therein contained," the absence of any kind of straining 

 apparatus should have aff"orded a sufficient caution against such a proposition, even 

 if no evidence of the actual mode of feeding had been extant. 



The trunk terminates with the vent, which is distant eight and a half inches from 

 the extremity of the snout. It is compressed, and its anterior part which lies between 



