XXX CLASSIFICATION OF UROCOPTID^. 



tions of the genera to one another will become clearer, and 

 it may be that some groups nearly similar in teeth will be 

 found to have diverged in other respects. It seems likely 

 that the genera Vrocoptis and Brachypodella will be further 

 divided into several genera each; although in the present 

 work I have not considered it best to make further generic 

 division, which would now rest upon purely conchological 

 features. Among other points to be ascertained are the rela- 

 tionships of Microceramus. 



In the Eucalodiince, there is no such strong differentiation 

 of the radula; and while the genera now recognized are cer- 

 tainly well characterized, their inter-relations are not yet 

 worked out satisfactorily, awaiting more material. Infor- 

 mation is especially needed upon the free retractor muscles; 

 and the amputated apical whorls of Eucalodium and of the 

 several groups of Coclocentrum call for further investigation. 

 Some such relation seems to exist between Spartocentrum and 

 Berendtia as between Mychostoma and Apoma, the second 

 group in both cases differing from the first in little besides 

 the reduction of the axis and the diminished number of 

 whorls. Coclocentrum, as now constituted, is somewhat het- 

 erogeneous. Another question arises regarding the relation- 

 ship between Eucalodium, Anisospira and Coclocentrum on 

 the one hand, and Holospira and Epirobia on the other. The 

 last two genera may be found to constitute a subfamily apart 

 from the others. 



The following classification is proposed in this work: 



Family UROCOPTIDyE Pils. & Van. 

 Subfamily EUCALODIIN^E C. & F. 



Genus Archegocoptis Pils. Genus Berendtia C. & F. 



Genus Eucalodium C. & F. Genus Holospira Mart. 



Subg. Oligostylus Pils. Subg. Holospira. 



Genus Anisospira Strebel. Sect. Eudistemma Dall. 



Genus Coelocentrum C. & F. Sect. Distomospira Dall. 



Subg. Liocentrum Pils. Sect. Haplostemma Dall. 



Subg. Elasmocentrum Pils. Sect. Bostrichocentrum 



Subg. Spartocentrum Dall. [Streb. 



