24 Notes on the Genus Pineria^ and on the 



of various groups of Cylindrella and M.acroceramtis^ and con- 

 sider that they constitute a natural family, characterized by the 

 presence, 1st, of a jaw of extreme thinness, and with folds 

 chevroned on the median line ; and 2d, of lateral teeth, more 

 or less palm-leaf shaped, disposed in very oblique rows, which 

 family they designate as CylindrellidcB. 



The authors proposed the following classification : — 



FAMILY CYLmDRELLIDyE. 



1. Geoup a. Cylindrella (sensic strido). 



Two lateral teeth on either side of the rachidian tooth ; mar- 

 ginal teeth of a very diflerent form, varying in nuuiber, 

 according to the species. 



This group comprises the sections Ajpoma^ Beck, or Casta, 

 Albers (including the sinistral species, C. gracilis, Wood, C. 

 elongata, Chemn., C. Agnesiana, C. B. Ad.); Trxiohelia {C. 

 Broolisiana, Gundl, &c.), and Mychostoma, Albers {C. costata, 

 Guilding, C. Bahamensis, Pfr. &c.). 



2. Group B. Callonia, Crosse and Fischer. 



Rachidian tooth with a very long cusp ; lateral teeth more 

 than two ; marginal teeth arranged obliquely in a continuous 

 line with the laterals, and not distinctly characterized. Only 

 one species known, C. Eliotti. 



3. Group C. Thaumasia, Albers {partim). 



Lateral teeth more than two ; marginal teeth similar to the 

 laterals, and not to be distinguished from them. 



This group includes the large species of Jamaica and Hayti, 

 and some of those of Cuba, but none of the species of Eucalo- 

 diuni. 



4. Group D. Lia, Albers {emend}) 



Lateral teeth verj^ numerous ; marginal teeth of the same 

 type as the lateral teeth, and not to be distinguished from 



