336 Prof. Bailey on Fossil and Recent Ivfusoria. 



Among the forms which occur at some of the locahties above 

 mentioned, and which I have not been able to identify with any 

 of those described by Ehrenberg, are the following : 



1. Biddulphia , n. sp.? (Fig. 24, 24a,) — This is some- 

 what allied in form to Denticella tridentata, but I have never 

 seen any lateral setse upon it. It may be recognized by the 

 curves at the base of the lines of constriction of the lorica. It 

 occurs sparingly at Rappahannock Cliffs, and is more abundant 

 at Brown's Mills, Ya. 



2. Triceratium , n. sp.? (Fig. 25.) — This species has 



each of its angles subtended by an arc of the circle, so as to form 

 with the sides a somewhat hexagonal figure in the middle of the 

 triangular faces. It occurs fossil at Meherrin River, and recent 

 at Charleston, S. C. 



3. Goniotheciumi . (Fig. 26.) — These forms consist of 



elliptical shield-shaped plates, with a large elevated umbone sur- 

 rounded by a narrow margin. They occur at Bermuda, Rappa- 

 hannock Clifls, Brown's Mills, &c. 



4. Lithocam.pe . (Fig. 27.) — This remarkablj'' perfect 



specimen of Lithocampe was found by me in the infusorial earth 

 from Piscataway, Md. 



There are also several species of Rhaphoneis occurring at most 

 of the localities, which I cannot determine positively ; one of the 

 most remarkable occurs abundantly at Rappahannock Cliffs, and 

 has very elongated rounded terminations, greatly resembling the 

 upper end of Sceptroneis Caduceus, (fig. II.) 



A species of Stauroptera from the locality at Meherrin River 

 is shown in fig. 28. It has not been found fossil at any other 

 locality. 



The following are offered as some of the general conclusions 

 drawn from the observations above recorded. 



1. The species at all the above mentioned localities are exclu- 

 sively marine. 



2. The different localities have many species in common, the 

 number of which will doubtless be increased by further obser- 

 vation. 



3. The species which appear to have been most extensively 

 diffused in the seas from which the fossil deposits were made, are 

 the very species which in the recent state appear to be cosmopo- 

 lites ; as for example, Actiniscus Pentasterias, Actinoptychus se- 

 narius, Coscinodisciis apiculatus, C. margiriatus, C. lineaius, 



