1815.] VON BUCH ON CYSTIDEA. 11 



tion of the monuments on the coast of Lycia. The formation of 

 the great Pampbylian plain may also be regarded as one of the 

 latest, though one of the most important events in the geological 

 history of this part of Asia Minor. 



2. Notice of a New Family of Crinoidal Animals, called Cystidea. 

 By Baron Leopold von Buch, For. Memb. G.S. &c. 



The Crinoidea are provided with long arms, penetrating plates, 

 which together form a kind of cup containing the viscera of the 

 animal. These arms, according to the discoveries of Mr. Thomp- 

 son, which have since been fully confirmed by M. Miiller of Berlin, 

 in his beautiful analysis of the Platycrinus, have the ovaries placed 

 at the base of pinnules attached to the arms. An ovarian orifice in 

 the cup would therefore have been useless, and is not present. 



In the most ancient formations there exist, however, bodies with- 

 out arms, and generally of a nearly spherical form. These bodies, 

 of which the cup closely resembles in all respects that of the Cri- 

 noidea, are always provided with an ovarian orifice, and further, 

 they also have an anus by the side of the mouth. This is an orga- 

 nization different from that of the Crinoidea, and it will be useful to 

 collect the various species into a group under a distinct name. 



The Cystidea are distinguished, — 



1. By having the mouth constantly at the apex and in the centre, 

 which is rarely the case in the Crinoidea. 



2. By being provided with an ovarian orifice, generally situated 

 in the upper part of the body or cup. This orifice is almost always 

 formed by five valves, pierced at their summit with a small hole. 



3. By having an anus not far from the mouth, and always on the 

 right of the ovarian orifice. 



The description of the various species forms the subject of a me- 

 moir in the Transactions of the Berlin Academy not yet published. 



The figures of Caryocrinus ornatus^ are intended to exhibit the 

 admirable symmetry of these bodies. Two large plates and two 

 small ones form the base. If from the intersection of the large ones, 

 each of which is composed of two small ones confluent and soldered 

 together, we draw an imaginary line to the summit, it is found to 

 pass through a lateral plate, having an angle at its apex, and not 

 truncated as the rest : beyond which and in the same direction is 

 placed the mouth. 



We have therefore here a bilateral arrangement — a right and left 

 side — distinctly shown ; and this arrangement exists in almost all the 

 Crinoidea, especially in such as have unequal basal plates, such as 

 PlatycrinuS) &c. 



* The figures of most of the species are given, together with a complete trans- 

 lation of M. von Biich's memoir, among the miscellaneous articles in the present 

 numher of the Journal. — Ed. 



