CErHEUS BIFIDATUS. 577 



wliorl of thin curved hairs, and there are a few similar 

 hairs on the hind legs, chiefly on the outside. There 

 are tactile hairs on all the legs, those of the anterior 

 pairs beiug very long. The tarsi are clothed with long 

 setiform hairs. 



Abdomen elliptical ; notogaster flat, ventral surface 

 arched, so that the notogaster stands much above the 

 cephalothorax. The cast notogastral skins of the larva 

 and nymph are carried flat on the back ; where the 

 larval skin forms a central shield, and the nymphal skins 

 almost concentric rings bordering it ; the centre of each 

 skin, however, is usually a trifle in advance of the centre 

 of that below it. The larval skin is arched and bordered 

 by about seventeen thin, curved, sparsely-serrated, 

 colourless spines, of which the hind one is central ; and 

 this skin has three pairs of similar spines on the noto- 

 gaster. Round the margin of each nymphal skin are 

 about twenty chitinous, brown, more or less cojiical 

 papillcB ; these gradually enlarge in size from the 

 anterior to the posterior papillse. Each papilla carries 

 an excessively long, slender spine of clear chitin sparsely 

 serrated. These may almost be considered as in a 

 condition between spine and hair, the anterior (except 

 the first pair) are mostly doubly-curved, and stifi*, or 

 nearly so, and are of similar form on the two sides of 

 the abdomen ; those nearer the posterior extremity are 

 more flexible and consequently vary more in form ; the 

 first pair are flexible, but their curvature is usually 

 equal on the two sides ; many of the spines are longer 

 than the whole length of the body, and, as they stand 

 out radially and border each cast skin, they give the 

 creature a most extraordinary appearance. Some of 

 the spines which project over the cephalothorax from 

 the different skins cross, and make a series of bilateral 

 figures, all diff'erent. 



La7'va. 



The appearance of this may be gathered from the 

 above description of the cast notogastral skin. The 

 VOL. II. 37 



