TRIGONOCERAS PARADOXICUM. 51 



Only one specimen has been, up to the present time, found in Ireland, viz. 

 M'Coj's type, figured in the "Synopsis" {loc. cit.). This was formerly in the 

 collection of the late Dr. Haines of Cork. M'Coy's figure of it is "restored," 

 unless it has suffered damage since it was introduced into his work. 



Locality. — Little Island, near Cork. 



Faynih) Tkigonockeatid.?:. 



Genus Teigoxoceras, M'Cotj, 1844. 



Trigon.keras PAiiADOXiccM, J. lie C. Soicerby, sp. Plate XVIII, figs. Sa,h,r, 



■ill, b, 5. 



lb'25. Obthocera pabadoxica, J. de C. Soicerby. Min. Conch., vol. v, p. 81. 



pi. cccclvii. 

 1&3C. Oethockbas PAUADOXICUM, J. Phillips. Geology ot Torksbire, pt. 2, 



p. 239. 

 1844. — (Tbigosoc£Bas) PABAD>ixicrii, F. Jl'Coy. Svnop. Carb. 



Foss. Ireland, p. 9. 

 18.55. — — — F. M'Coy. British Palaeo- 



zoic Fossils, fa?c. 3, 

 p. 573. 

 ISSO. Gtboceeas PABABOXicrii, L. G. de Koninck. Faune Cale. Carb. Belgique 



(Ann. Mu8. Hoy. d'Hist. Nat. Belgique, 

 torn, v), pt. 2, p. 7, pi. xxxii, figs. 3, 3 a, 3fc. 

 1S83. Teigoxocebas pabadoxicum, A. Hyatt. Proceed. Boston Soe. Xat. Hist., 



vol. iiii, 1S82— 3 (lbS4), p. 291. 

 1^91. GxBOCEKAS (Tbigoxocebas) pabadoxiccji, A. M. Foord. Cat. Fots. 



Cepb. Brit. Mus., pt. 2, p. 70, fig. 7. 

 1S93. Tkigo^ocebas paradoxiccm, A. Hyatt. Carboniferous Cephalopods. 



Second paper. Geological Survey of 

 Te.itas, Fourth .\nnual Report. 1S92. 

 p. 404. 



Description. — Shell rapidly tapering, "abruptly incurved towards the smaller 

 end, forming half a volution " (M'Coy), the rest of the shell gently curved. In a 

 given specimen it was found that upon a cord of 130 mm., subtending the con- 

 cave side of the shell, the greatest curvature was 20 mm. The section is 

 di:-tinctly shield-shaped, the ventral area slightly concave, the sides, at first 

 nearly straight, are curved below, converging towards the median line, where there 

 is a ridge or keel which is not very prominent. Two strong keels on each side 

 of the peripheral area run parallel to the marginal one (PI. XVIII, fig. 4 6). Th<» 



