430 



APPENDIX. 



divisions are seen, in each of whose centre runs a narrow 

 line, terminating at the margin in a little opening. The 

 internal partitions appear to lie between every two of these 

 narrow lines, so that as many as twenty-four rays may be 

 counted, but there are only twelve openings to be seen. 

 Diameter 1 -560th to l-480th. 



762. ACTINOCYCLUS quindenarius. Partitions not pre- 

 sent, disc having fifteen finely punctated rays. Found fossil 

 in the chalk marl of Oran, and alive in the waters of the 

 Cattegat. The discs of this species are more arched than 

 those of any other of the preceding ones. The fifteen 

 rays terminate in fifteen marginal openings. The ova 

 are distributed into forty- eight round, yellowish-brown- 

 coloured masses, placed around the bright central spot of 

 the body, or else appear united as one ball. Locomotion 

 was not perceptible. Diameter of fossil forms, 1 -560th; 

 of the living, l-560th to l-480th. 



763. ACTINOCYCLUS sedenarius. Disc divided, by in- 

 ternal partitions, into sixteen cells, and having sixteen finely 

 punctated rays. The ova, which are of a green colour, 

 form, in some, separate concentric masses; in others, a 

 single ball-like mass, placed in the middle of the body. 

 Locomotion not perceptible. Found alive near Cuxhaven. 

 Diameter of the shells I -290th. 



764. ACTINOCYCLUS octodenarius. Disc divided by in- 

 ternal partitions into eighteen cells, and having eighteen 

 finely punctated rays. This species is very similar to the 

 preceding, being only a little larger, and having eighteen 

 alternately dark and bright divisions, as many internal 

 septae, and marginal openings. The ova, in one specimen, 

 consisted of seven large yellowish green masses, placed 

 concentrically around the bright central spot of the body, 

 but which did not appear to be strictly confined to the 

 divisions or cells, which, most probably, arises from some 

 optical deception. It was remarkable that, in this 



