115 



columella. The surface is covered by rather thick transverse 

 striae almost as in Glandina costellata Sow. sp. 

 The Cyrena-bed: 11 specimens. 



Besides the above mentioned gastropods I have , in the 

 material from the Cyrena-bed which was brought home, found 

 some other species of which, on account of their bad state of 

 preservation, I have not even succeeded in determining the 

 genus. Rather frequently a slender, turreted form appears, 

 of which I have only seen sections ; it looks as if it might 

 belong to the genus Cerithium. Moreover Г have seen a couple 

 of specimens of a quite small form, which rather resemble 

 certain recent species of Planorbis. 



С Crustacea. 



18. Hoploparia groeniandica n. sp. 



Plate IV, figs. 1—2. 



In the concretions from the Coeloma-bed several specimens 

 of a macrurous crustacean have been found, but only one is 

 tolerably perfect and in a good state of preservation. This one 

 will therefore serve as foundation for the following description. 

 It is somewhat smaller than the other specimens which probably 

 belong to the same species. 



The carapace is rather long; its length reckoned from 

 the posterior margin to the base of the rostrum, 44 mm. 

 The greatest breadth of the flanks is near the middle and 

 is 25 mm.; the greatest thickness, which is near the posterior 

 margin, is about 17 mm.; but it has probably been a great deal 

 larger as the shell after the animal's death has become some- 

 what compressed. At a distance of 18 mm. from the posterior 

 margin is the cervical furrow which is deep and broad ; it first 



