102 ZOOLOGY. 



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

 the depth of 2435 fathoms. B. Aldrichianus occurred in 

 1850 fathoms, -latitude 1° 47' X., longitude 24° 26' W., ofl- 

 the coast of Brazil. AYith it and also near the Crozet 

 Islands occurred the interesting Hyocrinus Bethellianus 

 "Wyville-Thompson, which hears in some points resemblance 

 to the palaeozoic genus, Platycrinus. 



Pig. 64.— a, Pmtacrlnus caput^medusce, half nataral size; b, calyx-disk seen from 

 EDOve, nataral size.— From Brehm'a Thierleben. 



The most widely distributed species is the Rhizocrinus^ 

 lofotensis of Sars (Fig. 65), which is closely related to the 

 Bourguetticrinus of the chalk formation, and forms the 

 transitional type connecting the Apiocrinidm with the 

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



