42 TRILOBITA. 



Illjenus Portlockii, Salter, 1849. Caradoc Schists, Desertcreate, Tyrone. 



IHmtus crassicamla, Portl. 1843, Report Geol. Tyrone, &c. pi. x. figs. 7, 8. 

 I. Portlocldi, Salter, 1849, TJeciide li. Geol. Surv.' pi. ii. p. 3 ; id. 1859, Siluria, 

 2nd ed. Appen. p. 539 ; id. 18(37, Mon. Pal. Sec. pt. 4, p. 197, pi. xxvi. figs. 3, 4. 



Illaenus Eosenbergii, Eichwald, 1833. Caradoc, C'oniston, Sunny Brow, 



and Horton, Westmoreland. 



Illcenus Rosenherqii, Eichwald, 1833, Geogii.-zool. per Ingiiam, Tril. Obs. &c., 



t. iii. fig. 3? ; Salter, 1849, Mem. Geol. Surv. vol. ii. pt. 1, p. 338 ; M'Coy, 



1852, Svnop. Woodw. Miis. p. 172 ; Salter, 1867, Mon. Pal. Soc. pt. 4, 



p. 199, pi. xxLx. figs. 2-6. 



I. Murchisoni, Salter, 1852, Synop. Woodw. ]Mus. Appen. pi. i. G. figs. 33-35. 



Illaenus (Dysplanus) Thompsoni, Salter. Llandovery Eocks, Ayrshire, 



Pembrokeshire ; May-Hill Sandstone, 



Builth ; Tarannon Shale, Shropshire. 



Illcenus {Di/splaims) Thumpsvni, Salter, 1851, Quart. Journ. Geol. Soc. vol. 



vii. p. 171, pi. ix. fig. 3 ; id. 1867, Siluria, 3rd edit. ; id. 1867, Mon. Pal. 



Soc. p. 188, pi. xxviii. figs. 2-4, pi. xxx. figs. 8-10. 



lllipnopsis {Dysplanus) 27io7npsoni, Salter, 1865, Mem. Geol. Surv. vol. iii. p. 3C.0, 



pi. xi. B. fig. 1. 



Illaenus (Illaenopsis) Thomsoni, Salter, 1866. Arenig Eocks, Shelve, 



Shropshire. 



Illesnopsis Thomsoni, Salter, 18G6, Mem. Geol. Surv. vol. iii. pi. xi. B. figs. 1, 2, 

 pp. 256, 316 (not of the May Hill or Upper Llandovery list in p. 360, which 

 is a misprint for Illcenus Thomsoni) ; id. 1867, Mon. Pal. Soc. p. 213, pi. xx. 

 fig. 1. 



lUsenus (Illaenopsis ?) acuticaudata, Hicks, 1875. Tpper Arenig, 



Whitesand Bay. 

 Illaenopsis? acuticaudata, Hicks, 1875, Quart. Joiu'n. Geol. Soc. vol. xxxi. 

 p. 184, pi. ix. fig. 5. 



LICHAS, Dalmau, 1826. 



Lichas, Dalm. 1826, Pal^adema ; Salter, 1848, Mem. Geol. Surv. vol. ii 

 pt. 1, p. 340 ; Fletcher, 1850, Quart. Joum. Geol. Soc. vol. vi. p. 235 

 M'Coy, 1855, Pal. Foss. Irel. ; Murch. 1867, Siluria, 4th edit. p. 234 

 Salter, 1873, G.at. Camb. & Sil. Foss. p. 130. 



Peltura, Milne-Edw. 1840, Crust, vol. iii. p. 345. 



Metopias, Eichw. Urwelt Russl. 2nd pt. 



Arges, Bevrich, 1846, LTntersuch. iiber Tril. ii. p. 6. 



Calymene}, M'Coy, 1855, Pal. Foss. Irel. 



Trochurus, M'Coy, 1855, Pal. Foss. Irel. p. 151. 

 Distribution. Cambrian and Silurian. 



Lichas anglicus, Beyrich, sp., 1840. Wenlock Limestone, Dudley. 



Peltura BucUandi, Milne-Edw. 1840, Crust, vol. iii. p. 345, pi. 34. fig. 12. 



Argcs ani/licus, Beyrich, 1846, Untersuch. fiber Trilob. ii. p. 6, pi. 1. 



Lichas liuckla/idi, Fletcher, 1850, Quart. Journ. Geol. Soc. vol. vi. p. 235, 



pi. xxvii. figs. 1-5, & xxvii. bis. figs. 1 a, b. 

 L. anglicus, Siluria, 4th edit. 1867, p. 234, foss. 04. fig. 1, and p. 519; 



Salter, 1873, Cat. Camb. & Sil. Foss. p. 130. 



