324 Prof. Bailey on Fossil and Recent Infusoria. 



to me to be most novel and interesting ; and requested him to 

 name and describe the species. This request he has kindly com- 

 phed with, and in a letter dated Berlin, Aug. 10, 1844, he has 

 furnished me the names for the forms whose outlines I had sent 

 him, and also with the monthly report of the Berlin Academy for 

 June, 1844, which contains a list of 138 species, which he has 

 detected in the Bermuda Tripoli, together with short descriptions 

 of 9 new genera and 58 new species. 



It is but justice to Ehrenberg to state, that he has given me 

 ample credit for every fact, however unimportant, with which I 

 have furnished him. 



From Ehrenberg's report and letter above mentioned, and the 

 reference he makes to drawings of which I retained duplicates, 

 I have been able to identify most of the forms which he describes, 

 many of which are so remarkable that I believe the following 

 notice of them, accompanied by sketches of my own, showing 

 the most important generic characters, will not be unacceptable 

 to naturalists. I have also included the characters of some new 

 genera founded by Ehrenberg on forms previously included un- 

 der groups from which they are now very properly separated. 

 Many of these forms are of American type, and therefore a know- 

 ledge of them will be useful to students of our fossil infusoria. 



1. " Craspedodiscus, nov. gen. — Animal e Bacillariis Naviculaceis 

 liberum, Lorica simplex sequaliter bivalvis silicea orbicularis non con- 

 catenata, superficie cellulosa, prseter cellularum radiantem ordinem, 

 non radiata nee septata, sed margins structurae diversse tumido solubi- 

 lique late prsetexta." 



The forms of this beautiful genus resemble Coscinodisci sur- 

 rounded by a distinct tumid margin of cells much larger than 

 those upon the disc. 



A portion of Craspedodiscus elegans from Bermuda is shown 

 in fig. D. To the same genus is now referred the Pyxidicula 

 Coscinodiscus, Ehr. which occurs fossil in Virginia. 



2. " Heliopelta, nov. gen. — Animal e Bacillariis Naviculaceis libe- 

 rum. Lorica simplex sequaliter bivalvis silicea orbicularis (non conca- 

 tenata?) intus sepimentis imperfectis in loculos radiantes extus alterne 

 impresses divisa, centro Isevi anguloso, aperturis sub margine tot quot 

 radii adsunt magnis, spinulis in utroque latere sub margine crebris 

 erectis oppositis." 



