CYCLUS WRIGHTII. 251 



the carapace is only markedly interrupted by a greater degree of prominence in the dorsal 

 ridge just where it expands. The lobes are all roundly tumid, and, like the preceding 

 species, almost smooth. Cyclus torosus was obtained from the Carboniferous Lime- 

 stone of Little Island, Cork, by Mr. Joseph Wright, F.G.S. 



Species 3.— CYCLUS WRIGHTII :— H. Woodw, 1870. PI. XXXII, fig. 47 a, b. 



Cyclus Wrightii, H. Woodw., 1870. Geol. Mag., vol. vii, p. 555, pi. xxiii, figs. 5 



and 5 a. 

 — — H. Woodw., 1873. Brit. Assoc. Report, 7th Report on Fossil 



Crustacea, p. 304. 



This well-preserved form (which we have named in honour of the discoverer, Mr. Joseph 

 Wright, F.G.S., of Belfast, who has devoted much time and attention to the investigation 

 of the fossils of the Carboniferous Limestone of Ireland) was procured from the Limestone 

 of Little Island, Cork. 1 It is oval in form, being 2j lines in length, 2 lines in breadth, 

 and 2 lines in height. Cyclus Wrightii, like C. bilobatus, has a mimetic resemblance to 

 a Coleopterous Insect, but the disproportion between the anterior and posterior divisions 

 of the carapace is even greater than in C. bilobatus, the anterior part forming one fifth of 

 the entire length. A narrow, flattened border encircles four fifths of the carapace, the 

 anterior fifth apparently terminating abruptly at the margin without any border. The 

 dorsal ridge is prominent and broad, and extends from the anterior to the posterior 

 border, commencing as a narrow ridge behind. It spreads out into two successive 

 rounded expansions, and again contracts somewhat before reaching the cervical furrow, 

 in front of which it again becomes much wider, then contracting slowly towards the 

 front. A somewhat triangular lobe flanks each side of this dorsal line in front, whilst 

 two nearly round lobes are placed, one on either side of it, behind the cervical furrow. 

 Nearer the latero-anterior margin two other rounded lobes are formed, one on either side, 

 by a branch of the cervical furrow. 



The two great latero-posterior lobes of the buckler have a single corrugated ridge, 

 commencing very faintly at the posterior dorsal line, and running forward and curving 

 around the sides of the carapace, and becoming more strongly marked near the cervical 

 furrow. 



The surface is smooth or slightly and very finely granulated. 



1 Another specimen, obtained by Professor Harkness, F.R.S., from the Carboniferous Limestone of 

 Keisley, near Appleby, Westmoreland, appears to be referable to this species, but the intractable nature 

 of the matrix renders it impossible for me to work it out satisfactorily (see Prof. Harkness's paper, 

 ' Quart. Journ. Geol. Soc.,' 1865, vol. xxi, p. 243, &c). 



