CHONDRACANTHID^. 325 



some distance from these organs, about the middle of the 

 head, is situated the mouth. 



Rathke and Nordmann describe a pair of mandibles 

 attached to the mouth, and a pair of small organs, which, 

 according to M. Edwards, is a second pair of foot-jaws. 

 The mandibles are very small, and are beset along their 

 entire length with very fine teeth ; and the foot-jaws are 

 somewhat larger, and composed of a stout basal joint and 

 a horny, curved hook. Immediately below these we see 

 a third pair of foot-jaws, considerably larger than the pre- 

 ceding, and consisting of two tolerably large joints, and a 

 moveable, moderately large, and curved claw. 



The thorax is connected to the head by means of a sort of 

 neck, which in some species is of considerable length, and 

 occasionally gives origin to one or two pairs of processes, 

 which project laterally. The thorax itself is of consider- 

 able size, and varies much in form and appearance ; it 

 gives origin to several pairs of cartilaginous-looking pro- 

 cesses from its sides, and a pair of ovarian tubes of con- 

 siderable length. Between these ovarian tubes is situated 

 the abdomen, which is exceedingly small, indeed almost 

 obsolete. 



Male. The males are extremely small, about half a line 

 long, and do not in the slightest degree resemble the 

 female. They are of a more or less pyriform shape, with 

 a very large head, an articulated thorax, and possess very 

 large foot-jaws. They are always found attached to the 

 posterior extremity of the female, between the anus and 

 the right sexual aperture. 



In general only one male is found upon each female, 

 but in some species there are two. As I have mentioned 

 above (p. 321), doubts have been thrown upon these little 

 creatures being males. Burmeister, for instance, supposes 

 they may be only unformed oryouthful specimens. Rathke, 

 however, agrees with Nordmann and Kroyer, in consider- 

 ing them to be really males. " The circumstance," he 

 says, " that those beings which we find in the sexual 

 apertures of the female Lernese, show always in the same 



