324 BRITISH ENTOMOSTKACA. 



first gave to it the name of Chondracanthus, from the 

 cartilaginous sort of spines which cover the body. 



Cuvier, in his ' Regne Animal/ figm'es two distinct 

 species, but only shghtly indicates them in a note ; and 

 Blainville, in his Monograph of the Lerneadae, in the 

 ' Journ, de Phys.' for 1822, describes nine more, under 

 the different generic names of Lernacantha, Lernentoma, 

 and Lernanthropus. None of these authors, however, 

 enter into any lengthened details with regard to the struc- 

 ture or habits of these curious little creatures ; but a few 

 years after the publication of Blainville's memoir, atten- 

 tion was called to their history by Nordmann, who, in 

 his ' Mikrog. Beitr.,' 1832, has given us much very in- 

 terestino- and valuable information with regard to them. 

 He was followed by Burmeister and Kroyer, the latter 

 of whom has especially devoted his attention to the 

 anatomy and physiology of several species of the family. 

 Since then, Rathke has followed up these inquiries with 

 great diligence, and has added much to our knowledge 

 of the two sexes, as well as the internal anatomy of the 

 female. 



Anatomy, ^c. — Female. The body of these animals pre- 

 sents no trace of articulations, though two or three divisions 

 may in general be easily recognised, consisting of the head, 

 which has in many instances a sort of neck, and the 

 thorax. The abdomen is nearly quite rudimentary. The 

 head is small, and generally not very distinct from the 

 body. It is slightly convex and smooth dorsally, and has 

 a small groove running down the centre. In many of 

 the species it contracts towards its lower part, forming 

 a short neck before it joins the thorax. 



The eyes are totally wanting. The antennae are only one 

 pair, rather flattened generally, and very indistinctly jointed. 



Immediately beneath the antennse we see the first pair 

 of foot-jaws ; small, and consisting of a short but stout 

 basal joint, and a hard, curved claw or hook, by means of 

 which the animal assists in fastening itself to its prey. At 



