F. R. Cowper Reed — On the Genus ConocorypJie. 251 



Conocoryphidfe, which also includes the genera Atoiys, Ctenocephalus^ 

 and Bathynotus, besides others of subgenerio rank or of less 

 importance. The characters of the family are given (op. cit.) as 

 follows : — 



" Free cheeks very narrow, forming the lateral margins of the 

 cephalon, and bearing the genal spines. Fixed cheeks large, 

 usually traversed by an eye-line extending from near the anterior 

 end of the glabella. Facial sutures running from just within the 

 genal angles, curving forward, and cutting the anterior lateral 

 margins of the cephalon. Eyes rudimentary or absent. Thorax 

 with from fourteen to seventeen segments. Pygidium small and of 

 few segments. Cambrian." 



The characters of the genus ConocorypJie are given as follows : — 

 " Cephalon semicircular ; genal angles produced into spines ; 

 glabella distinctly lobed, wide behind, and contracted in front, 

 not extending to the frontal border. Fixed cheeks very large, with 

 conspicuous furrow parallel to the anterior margin ; free cheeks 

 narrow, marginal ; thorax of fourteen segments." 



The same author, Dr. Charles Beecher, who has written the 

 article on trilobites in the book above quoted, published the same 

 diagnosis of the family Conocoryphidse in 1897,^ and included in it 

 the following genera and subgenera : — 



Conocoryphe, Corda { = Conocephalites, Barrande). 



Anencanthus, Angeliu. 



Atops, Emmous. 



Avalonia, Wulcott. 



Bailiella, Matthew { = SaUeria, "Walcott, ^nA. Erinnys, Salter). 



Bathynotus, Hall. 



Carausia, Hicks. 



Ctenocephalus, Corda. 



Dictyocephalus, Bergeron. 



Eryx, Angelin. 



Harttia, Walcott. 



Toxotis, Wallerius. 



Matthew - has contributed much to our knowledge of the genus,. 

 and his writings deserve careful study. 



The usage of the generic name ConocorypJie in Britain has on 

 a previous occasion been briefly criticized by the present author,' 

 and some of the British species assigned to other genera. In 

 discussing them here more in detail it will be convenient to take 

 them alphabetically. 



ConocorypJie ahdita (Salter, Mem. Geol. Surv., vol. iii, 1866, 

 p. 306, pi. V, fig. 13). — This species is at once seen to possess 

 fundamental difi'erences from ConocorypJie, sens, str., in the large 

 well-developed eyes and in the course of the facial suture. The 

 presence of pits in the marginal furrow of the head-shield suggests 

 that it should be referred to either Euloma or ApatoJcepJialus, and 

 the position of the eyes, their relative size, the eye-lines, and the 



1 Amer. Journ. Sc, vol. iii (1S97), p. 180. 



2 Trans. Roy. Soc. Canada, vol. ii (1884), sect, iv, pp. 102, 103. 



3 Geol. Mag., Dec. IV, Vol. V (1898), pp. 495, 496. 



