226 J. F. BLAKE ON" THE KIMMERIDGE CLAY OF ENGLAND . 



Portlandian species. It agrees in shape and ornament exactly ; but 

 the lip (which is broken) seems to be produced anteriorly to a short 

 canal. 



Lower Kimmeridge, Market Rasen. 



Trochus excavatus, n. sp. 



Angle of spire about 30°; 5 whorls visible, surface of whorls 

 angular, with an elevated ridge in the centre ; the space between 

 these ridges is uniformly concave, the separation of the whorls 

 being in the centre of the concavity ; the whole is ornamented with 

 numerous narrow inconspicuous riblets with wider concave spaces 

 between ; and the upper edge of the ridges is obscurely fimbriated. 

 Height \ inch. 



Lower Kimmeridge, Horncastle. 



A larger specimen is in the Jermyn-Street Museum, from Wootton 

 Bassett. 



Trochtjs retrorstts, n. sp. 



Angle of spire 45° ; 5 whorls visible ; angular at the lower two 

 thirds, where it is swollen, with a line of large knobs. There are 

 also two other rows above, and one below, the four being connected 

 by irregular low transverse risings, having a direction backwards 

 and downwards, and giving the knobs a slightly longer axis in that 

 direction. 



Yery similar to Trochus biornatus (Goldf.) of the Inferior Oolite, 

 but has two rows of knobs above the large row, and a rather smaller 

 angle of spire. 



Length ^ inch. 



A single specimen from the upper Kimmeridge, Fulletby brick- 

 yard. 



Dentalium Qttenstedti, Blake. Quenstedt, 'Jura,' tab. 98. fig. 20. 



Quenstedt does not give a name to the Dentalium figured by him, 

 which does not appear to differ from those found in the Kimmeridge 

 Clay generally throughout England. I therefore propose the above 

 name in accordance with a now accepted custom. 



Cardites striatulum (Sow.). 



Cardium pesolinum, Cont. ; G. lepidum, Sauv. and Rig. 



I cannot distinguish the numerous Protocardia that occur in all 

 the horizons from one another, or from G. striatulum, although 

 Dr. "Waagen names the one in the upper beds O. loiharingicum 

 (Buv). The Gardium pesolinum (Cont.), which Etallon considers a 

 synonym of his G. eduliforme, is a much more transverse shell, and 

 occurs at Weymouth. It is probably this that is recorded under the 

 latter name by Dr. "Waagen. Mr. Topley regards G. lepidum as also 

 a variety of G. striatulum. 



Lucina substriata (R'6m.).=L. Elsgaudice (Cont.). 



