344 



THE VOYAGE OF H.M.S. CHALLENGER. 



Genus Metacrinus (Wyville Tliomsou, MS.), P. H. Carpenter, 1884. 



Fourradials; 

 tlie second 

 a syzygy. 



Eight to twelve inter- 

 nodal joints witli hori- 

 zontal ridses. 



Ten to 

 thir- 

 teen 

 inter- 

 nodal 

 jO'ints. 



Lower parts of 



rays smooth. 

 Forty-five cu'- 

 rus joints. 



Ridges incomplete, 



Ridges continuous. 



Thirteen internodal joints with in- 

 curved sides. Interarticular 

 pores to thirteenth node. 



Ten or twelve internodal joints V 

 with iiat sides. Interarticular > 

 pores to tenth node. j 



Lower parts of rays have raised distal edges. 

 Sixty-five cirrus-joints. Interarticular pores to 

 eighteenth node. 



Six to ten internodal joints with nearly flat sides, 

 articular pores to about the sixth node. 



Inter- 



1. angulatus, n. sp. 



2. cingulatus, n. sp. 



3. murrayi, n. sp. 



4. nobilis, n. sp. 



swperhus, P. H. C. 



5. varians, n. sp. 



Eadials irre- 

 gular; usu- 

 aUy five 

 or six ; the 

 second and 

 also the 

 fourth 

 often a 



syzygy. 



Six radials ; 

 the second 

 and fourth 

 syzygies. 



Seven to nine internodal joints; the larger ones with a strong 

 median girdle. 



Eleven or twelve smooth internodal joints, 



' Three ray -divisions. Cirrus-facets as high as 

 the nodal joints. Five to eight internodals with 

 horizontal ridges. 



Six to 

 nine 

 inter- -i 

 nodal 

 joints. 



Four ray-divi- 

 sions. Nodal 

 joints higher - 

 than cirrus- 

 facets. 



Stem with strong interradialiidges \ 

 and nearly smooth, slightly (_ 

 hollowed sides. Seven or eight i 

 internodals. ) 



I 



Eight or nine internodals, ■n'ith ^ 

 flat tubercular sides. Angles of 

 nodals enlarged. 



I 



6. moseleyi, n. sp. 

 rotundas, P. H. C. 



7. iDyviUii, n. sp. 



8. costatus, n. sp. 



9. nodosus, n. sp. 



Tenor 



eleven 

 inter- 

 nodal 



joints. 



Stem pentagonal, with a tubercle at each angle \ 



and ridges on the sides, but not forming a \ 10. intevnqjtiis, n. sp. 

 complete girdle. Usually eight distichals. j 



Rounded stem without ridges. Usually ten dis- 

 tichals. 



The "Vega" specimen. 



Seven internodals with median tubercles; Infra-nodals not 

 incised. 



Angles of 

 stem sharp 

 and pro- \ 



ducedout- ! Eleven internodals with shght horizontal ridges 

 wards. [ nodals not incised. 



} 



\ 11. tuberosus, n. sp. 



Infra- 



:'a- ( 



stewarti, P. H. C. 



