106 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



the latter has published his description.) As the Tennessee fossil has priority, I 

 will continue to consider it as Asterias antiqua. 



The plate which accompanied the description in the transactions mentioned above> 

 does not give the true figure of this Asterias, I subjoin here a better representation 

 under figure 1. 



I stated in the memoir (loco cit.) that other Asterias occurred in the strata of Ten- 

 nessee. One of them after proper investigation I consider merely a parasite. Of 

 this parasitic fossil two individuals are attached to the interior surface of an Orthis 

 formosa, the one is 8 mil. ms. from the tip of one of the rays to that of the opposite 

 ray, while the other is microscopic. 



It occurs in Decatur County, Tennessee in Silurian Limestone. The second above 

 mentioned although very mutilated, I will now describe under the name of Comatula? 

 prisca— and the third under the name of Astrias tennesseex. 



The Asterias antiqua is a rare fossil. — The specimen here figured is the only one 

 that I have seen — very rarely fragments of it are found. They are generally so incor- 

 porated with the limestone, that it is impossible to develop any from its matrix. 

 The one which is here figured was brought to light by erosion; it fortunately lying 

 parallel to the eroded surface; — the fossil, being likewise carbonate of lime, is also 

 more or less eroded at its surface. It was found in the Silurian limestone on Har- 

 peth River, Davidson County, Tennessee. Associated with Spirifer lynx [Platy- 

 strophia biforata lynx], Cyathophlla [Streptelasma], Orthis [Dalmanella testudinaria], &c. 



The only starfish in the Troost collection is in the possession of 

 Prof. Charles Schuchert. He informs the writer that Hall's de- 

 scription of this specimen is erroneous and that it belongs to a 

 new genus. A description of both genus and species will soon be 

 published by Professor Schuchert. 



In the absence of the specimen no changes or corrections could 

 be made in Troost's description. 



FOSSILS OF UNCERTAIN RELATIONSHIP. 



Asterias tennesseese. — The specimen described under this name is 

 a large silicious pseudomorph, the character of which is well shown 

 by Troost's figure (plate 8, fig. 11). Its parts being arranged on 

 a plan of five, the pseudomorph probably had some portion of an 

 echinoderm as a basis for its growth, but the original structure is 

 too completely obliterated to determine what this may have been. 



The specimen was found in the Tullahoma formation of Cannon 

 County, Tennessee. 



Cat. No. 39913, U.S.N.M. 



Comatula prisca. — The specimen to which Doctor Troost has 

 given this name is missing from his collection. The figure shows 

 an approximately circular body with eight irregular rays. It is 

 probably the root of a crinoid. 



