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 opportunity 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, cylindrical, parallel, and vertical, accumulated in 

 bundles, by intermediate and transverse septa. Radiating 

 lamellae within the tubes. 



It differs from tubipora in its tubes being lamellated, 

 and, from stylina, in having no central style. 



1. Sarc. perforata. This species is only known recent. 



2. Sarc. 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. 



Caryophillia. 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 

 madreporse, in which they were placed by Linnaeus, and 



