32 



THE IXORGANK' CONSTITUENTS OF MARINE INVEKTEBR.\TES. 



analysis of an ophiuran, Astrophyton, by L. Schmelck,'' remains to be noticed. The accompany- 

 ing data are a.s follows: Locality, station .37 in the North Sea: latitude, 7S° 48' N.: longitude, 

 8° 57' E.; depth, 199 meters; bottom temperatme, 1.1° C. 



Analysis of Astrophyton. 



In this, as in Schmelck's analyses of starfishes, the magnesium carbonate is high for the 



temperature given. 



5. HOLOTHURIANS. 



Although the holothurians are of slight importance as contributors to the marine sediments, 

 it seemed desirable to compare a few of them with the other echinoderms. Four holothurians 

 were therefore analyzed, but their organic matter was so vastly in excess of their hard parts 

 that the analyses, with one exception, are far from satisfactory. However, the data, which are 

 not without some significance, are as follows: 



1. ffolothuria floridana Pourtalfes. Fajardo, Porto Rico. 



2. Cucumaria frondosa (Gunnerus). k northern cold-water species, precise locality unknown. 



3. Trochostoma intermedium Ludwig. Off Cerros Island. Calif. Weight of sam|)le, 0.2204 gram. 



4. Trochostoma intermedium. Albatross station 3307, in Bering Sea; latitude, 66° 12' N.; longitude, 172° 55' W. 

 depth of water, 130 meters; bottom temperature, 3.3° C. Weight of sample, 0.1175 gram. 



Analyses of holothurians. 



In No. 2, 0.31 per cent of matter soluble in water was found, which raises the summation; 

 to 100.19. 



Of these analyses only the first is reducible with any certainty to standard form. The 

 percentage composition of the inorganic portion of the specimen then becomes — 



SiOj 0. 15 



(Al,Fe)203 34 



MgCOs 13. 84 



CaCOs 83.29 



CaSO, 2.38 



CajP.Os Trace. 



100. 00 



»« Schmelck, L., Norske Nordhavs Expcd., No. 28, p. 129, 1901. 



