310 DESCRIPTION OF {Tolygastrico. 



the genus Actinoptychis, to contain all the species of Adinocychi, 

 having internal septa: all such, therefore, should he excluded 

 from the present genus. They are continued here on account of 

 their having received their original appellation and position in this 

 genus from Ehrenherg. It is therefore to he rememhered, that those 

 species described as having internal septa, are now Actinoptychi, with 

 the same specific names. 



AcTiNOCYCLTTs quatuordenarius, with fourteen rays, and as many in- 

 ternal partitions, sub-dividing its area into distinct cells (loculi.) 

 Diameter 1 -480th. Found in the North Sea. Cushaven. 



Of many remaining forms, it will suffice to indicate the number of 

 radii, and the locality and dimensions. 



A. ternarius, with three rays. In chalk marl. 

 A. quaternariiis, with four septa and rays. Same habit. Yirginia. 

 Diameter 1 -552th. 



A. quinarius, with five rays ; same habit. Fossil in chalk marl 

 of ^gina, &c. 



A. nonarius. — Septa absent; rays nine, finely punctated. Found 

 both fossil and alive. The single discs of the fossil forms are 

 generally without margin : they are sometimes quite perfect, but 

 often in broken pieces. In the living creatures, the gi'anules 

 are yellow; locomotion not observable. Diameter 1- 720th. to 

 1 -650th. 



A. denarius. — With ten rays, fossil in the chalk marl of Oran ; 

 and living in the waters of the Cattegat. 



A. U7ule}iarms. — Partitions not present, rays eleven, finely pimc- 

 tated. Found alive and fossil. The discs of the fossil forms are 

 destitute of margin, and are single, whilst those of the live creatures 

 have a broad edge and are double. In those specimens in which the 

 margin is absent, there exists as many roimd openings as there are 

 punctated rays. Diam. 1 560th. to 1 -480th. 



A. hiscnan'us. — Septa absent, rays twelve, finely punctated. Found 

 fossil and alive with the three preceding. The fossil fonns are 

 sometimes smaller than those of the living, but mostly about equal. 

 In the live condition, gi-anules are visible, as twenty-two greenish 

 masses around the colourless spot in the ccnti'e of the body. NeitJior 

 marginal openings nor locomotion have been satisfactorily seen. 



