504 ASTEROLAMPRA. 



GENUS 166. ASTEROLAMPRA EHR., 1844. 



Rays all equal or emanating 

 from the centre of the valve. 



This section consists of 36 

 species, the greater part of which 

 are fossil, and most are found in 

 the Barbadoes deposit. Fig. 250 

 represents one of the forms living 

 at the present day, A. Grevillei 

 Wall., var. Adriatua Grun. 



Fig, 250. Asterolampra Grevillei var. Adriatica. 



GENUS 167. ASTEROMPHALUS EHR, 1844. 



Fig. 251. Asteromphalus 

 reticulatus. 



Valve having two of the compartments 

 punctate, approximate, separated by a 

 narrower ray, and on one side not going quite 

 to the margin, and on the other side often 

 going beyond the centre of the valve. 



About forty species of Asteromphalus have been 

 described, a good number of which are still found 

 living, many also in the Arctic Ocean as well as in 

 the tropical seas. Some species are very cosmo- 

 politan, such as A.flabellatus (Bwb.) Grev., the only species which has been 

 met with in the North Sea (at Teignmouth by Grove), in Ascidians, and also 

 found in Campeachy Bay, Yokohama (Japan) as well as in Corsican moss, 

 from the Mediterranean, in Peruvian Guano, and in the Java Sea. 



Asteromphalus flabellatus (Breb.) Grev. is characterised by its sub-elliptical 

 valves, its conical finely reticulated compartments, often transversely truncate, 

 and by its median ray straight or very gently curved. Its diameter varies from 

 4 to 6 c.d.m , the minor axis never being more than 4 to 5 c.d.m. 



Figure 251 represents A. rcticulati/s Cleve, remarkable for the large cells of 

 its compartments. It is found in a living slate at Java. 



