78 



periphery being circular, it is angular, and generally either 

 pentagonal or hexagonal. In a third species, the fossil is of 

 a compound construction, being formed by the union of 

 polygonal, chiefly hexagonal tubes. This fossil has a highly 

 ornamented surface ; a projecting sharp ridge surrounds 

 every star ; the styloid projecting axis rises from a depres- 

 sion in the centre, and from its sides the surrounding 

 lamellae ascend with an undulating sweep to the acute 

 surrounding ridge ; the whole giving to each star some- 

 what of a floriform appearance. A small portion of this 

 fossil is represented PI. x. fig. 5. 



Not having the opportunit}^ of reference to the specimen 

 referred to by Lamarck, the classification of these fossils 

 must be indeed considered as conjectural: but it must be • 

 observed, that they appear to accord with the characters of 

 stylina; and that there does not appear to be any other 

 genus in which they can be placed. 



Sarcinula. — A stony polypifer, formed in a free, sim- 

 ple, thick mass, by tubes united together. The tubes 

 numerous, cylindri^cal, parallel, and vertical, accumulated in 

 bundles, by intermediate and transverse septa. Radiating 

 lamellae within the tubes. 



It differs from tiihipora in its tubes being lamellated, 

 and, from stylina^ in having no central style. 



1. ^arc. perforata. — This species is only known recent. 



2. Save, organum. — This is described as being found recent in the 



Red Sea. Fossil specimens are also found on the coast of 

 the Baltic. — Madrep. Organum. Am. Ac. Tab. iv. fig. 6. 



CaryopliiVJa. — A stony fixed polypifer, simple or ra- 

 mified; the stem and branches rather turbinated, and 

 striated longitudinally, each being terminated by a cell, 

 radiated in a stelliform figure. 



These substances are separated by Lamarck from the 

 madreporae, in which they were placed by Linnaeus, and 



