•32 MR. E. S. COBBOLD OST THE TRILOBITE EAENA [March 1913, 



Subgenus Strenuella Matthew '? 

 Agraelos (Streneella ?), spp. indet. (PL II, figs. 12«-14c.) 



Several fragments of cranidia [1398, 1847, 1878 c], with strongly- 

 marked features, a large and prominent glabella, but with only a 

 medium-sized eye-lobe, suggest a reference to Matthew's subgenus ; 

 in two specimens a strong nuchal spine, projecting horizontally 

 backwards, may be noted. 



Conocoryphe Corda. 



Subgenus Conocoryphe, sensu striclo, Gronwall, 1902. 



■Conocoryphe (C.) .eqealis Linnarsson. (PL III, figs. 18 a-18 c.) 



G. Linnarsson, Sver. Geol. Undersokn. ser. C, No. 54 (1883) p. 25 & pi. iv, 



figs. 12-15. 

 K. A. Gronwall, Danmarks Geol. Undersog. ser. 2, No. 13 (1902) p. 92 & pi. i, 



fig. 22. 



Six cranidia [1393, 1838, 1842, 1843, 1S68, 1869] from the 

 Breccia-Bed are apparently identical with Linnarsson's species. 



They are in very close agreement with his figures and descriptions, 

 but the matrix of the bed is too coarse to preserve any delicate 

 markings on the surfaces of the casts. 



In the specimen figured the missing parts, shown in outline, are 

 restored from the external impression : but one pair of glabellar 

 furrows is visible ; the ' ocular ridge ' is faintly traceable for a short 

 distance only across the cheek ; and in the view from above the 

 facial sutures appear to be nearly straight. 



The convexity ratio is 1 : 3 # 7. 



•Conocoryphe (C.) beeo Hicks. (PL III, figs. 17 a-17 c.) 



1865. J. W. Salter, Rep. Brit. Assoc. (Birmingham) p. 285. 

 1868. J. W. Salter & H. Hicks, Q. J. G. S. vol. xxv (1869) p. 52 & pi. ii, 

 fig. 8. 



Pour specimens of cranidia [1388, 1391, 1844, 1845] from the 

 Breccia-Bed are referable to this species. They are preserved as 

 internal and external casts, but the latter are the more fragmentary. 

 One specimen [1391] is so much distorted that its proportions 

 •cannot be made out ; but the external cast is valuable, as giving 

 indications that the surface was strongly granular or tuberculate. 

 The figured specimen [1388], which is practically complete, differs 

 a little from the type as described and figured by Hicks. It has a 

 proportionately larger and less tapering glabella, the triangular 

 boss of the anterior margin does, not reach so far back, and the 

 glabellar furrows are not very clearly marked. 



The length of the head-shield is about 13 millimetres and the 

 •convexity ratio is about 1 : 4. Other specimens measure 10 

 and 4*5 mm. in length of head-shield. 



The shield figured in PL III has suffered a curious distortion 

 before fossilization, parts of the left cheek and posterior margin 



