TRILOBITA. 



367 



it from the preceding by any rigid definition. Its members 



resemble the Paradoxidce in general characters, but the 



glabella is narrow in front, or, at any 



rate, not dilated in this region, and the 



tail is usually moderately developed, 



while the thoracic rings are not so 



numerous as in the typical forms of the 



latter. The type-genus is Conocoryphe 



or ConocepJialites (fig. 221, d and /), 



which has resemblances to both Olenus 



and Calymene, its glabella approaching 



that of the latter in its comparatively Fig 223 _ _ ulenvs micru _ 



great posterior width and its contraction " from tlie Li nguia Flags. 



(After Salter.) 



in front. Eyes are usually, but not 

 always present ; the facial sutures are discontinuous ; the 

 fixed cheeks are large and the free cheeks small ; and 

 there are fourteen or fifteen body - rings, while the tail 



Fig. 224. Angelina Sedgivickii, in its natural condition, and distorted by cleavage. 

 Upper Cambrian. (After Salter.) 



has from two to eight rings. The genus is represented 

 by very numerous species in the Upper Cambrian. El- 

 lipsocephalus (fig. 221, b) is related to the preceding, but 



