THECIDIUM 



sent only acquainted with one^ which we have repre- 

 sented; it has been brought rarely, in company with the 

 common red coral, from the Tuscan Seas : some French 

 Savans have considered it as a Crania, but it is evidently 

 distinct from that Genus, inasmuch as it has hinge pro- 

 cesses, which the Crania has not. The fossil species are 

 more numerous, we suspect one of them has been pub- 

 lished by Lamarck as a Terebratula, under the name of 

 T. pumila, but his reference to Magas pumila of Mineral 

 Conchology renders this somewhat doubtful. 



Those that we have seen appear to belong to the 

 Chalk, and have been brought only from Maestricht ; 

 and from Orglandes in Normandy. 



We have represented in our plate the following, viz. : 



Fig. 1. Thecidium pumilum, Terebratula pumila? Lam. showing the two 

 V alves together. 



2. the same, showing the inside of both valves. 



3. — digitatum. Nob. Valva superior interne lamellis digitatis. 



4. recurvirostre, De Fr. 



5. insides of the same. 



6. from the Mediterranean ; we do not venture to name this 



species, because we will not interfere with De France's unpublished account of 

 this Genus. 



7. insides of the same. 



