274 



THE VOYAGE OF H.M.S. CHALLENGER. 



upper plate, and from it issues the tentacle (r), while below is attached the rough, 

 cylindrical tentacle scale or arm spine. 



In several respects this genus leans towards the Ophiuridse ; as in its large teeth in 

 a single row, its solid radial shields, and its well formed under arm plates. 



Table of Species of Astroschema. 



So 





r3 

 c3 



CD (p 



3 B 



3 3 



3 o ° 



fl O CD 



Width of Arm 



to diameter 



of Disk. 



1 :3 

 1 :3 



l:3i 



1 :2i 

 1 :2h 



1 :3 



1 :U 



1 :3 



1 :4 

 1 :4 



1 :7 



Grains in 



1 mm. long 



on upper arm 



at its base. 



4-5 



9-15 



7-8 



6-7 



12 



8-9 

 6-9 



Disk spines set on little plates which, 

 pave the disk and arms. 



Disk grains sharp, even far out on 

 arms. Tentacle scales not any- 

 where longer than a joint, and 

 scarcely clubbed. 



Grains far out on arms, rounded. 

 Tentacle scales often as long as 1| 

 joints, but scarcely clubbed. 



Disk grains close-set, smooth, and very 

 large. 



Disk grains very fine, smooth, and 

 even. Two tentacle scales do not 

 begin till beyond the eighth pore. 



Arms short. Disk flat and even. 

 Under tentacle scale at end of arm 

 becomes a compound hook. 



Mouth tentacles in tubes. Lower 

 tentacle scale, near end of arm, 

 very long but not clubbed. 



Disk grains spaced and arranged in 

 concentric lines. 



No tentacle scale till fourth pore, then 

 one till the twelfth, after which 

 two (an ill-defined species). 



Arms extremely long and thin 



Arm much higher than wide. 



Astroschema h orridum. 

 Astroschema oligactes. 



Astroschema tumidum. 



Astroschema arenosum. 

 Astroschema Iceve. 



Astroschema salix. 



Astroschema rubrum. 



Astroschema steenstrupii, 

 Astroschema sulcatum. 



Astroschema tome. 

 Astroschema brachiatum. 



Astroschema intectum. 



