184 



ZOOLOGY. 



to Rhizocrinus, and was dredged in the Bay of Biscay at 

 the depth of 2435 fathoms. B. Aldrichianus occurred in 

 1850 fathoms, latitude 1 47' K"., longitude 24 26' W., off 

 the coast of Brazil. "With it and also near the Crozet 

 Islands occurred the interesting Hyocrinus Bethellianus 

 Wyville-Thompson, which bears in some points resemblance 

 to the palseozoic genus, Platycrinus. 



Fig. 127. a, Pentacrinux caput-meduAce, half natural size; t>, calyx-disk seen froitt 

 above, natural size. From Brehm's Thierleben. 



The most widely distributed species is the Rhizocrinus 

 lofotensis of Sars (Fig. 128), which is closely related to the 

 Bourguetticrinus of the chalk formation, and forms the 

 transitional type connecting the Apiocrinidce with the 

 free-moving, unstalked Antedon. It occurs at the depth of 



