ANNELIDS. 



15 



was not sought for. A single analysis of M. braziliensis by L. R. Lenox " gave the following 

 composition: 



CaCOa 93. 80 



MgCOa 2. 14 



CaSO* 2.08 



SiOa 03 



(Al,Fe)oO, 07 



98.12 



It is interesting to note that the Brazilian species is the richest of all in magnesia, although 

 it is poor in comparison with the echinoderms and alcyonarians. As reef builders the millc- 

 pores contribute little to the doral rock but carbonate of lime. 



In an analj'sis of MiUepora cervicornis, by A. Damour,'* 8.51 per cent of magnesium carbonate 

 is reported. The name, however, belongs to a fossil species, and the specimen analyzed was at 

 least partly fossilized. Its locality is given as Brehat, Manche, France. 



ANNELIDS. 



The curious tubes formed by marine worms probably conti-ibute little to tlie sediments. 

 They are, however, of some interest in an investigation df this kind, and for that reason six 

 analyses of them have been made, as follows: 



1. Filograna implexa Berkeley (Serpula complexa). Scarborough, England. 



2. Protula tabularia (Montagu) {Serpiila tabularia). Locality unknown, probably British. 



3. Eydroides diantluis Verrill. Vineyard Sound, Mass. 



4. Leodice polybranchia Verrill. Off Marthas Vineyard, Mass. 



5. 6. Hyalinmcia artifex Verrill. Off Marthas Vineyard, Fish Hawk station 1025; depth of water, 384 meters; 

 bottom temperature, 7° C. Two analyses, of different samples; the tubes of this annelid, on ignition, gave an inorganic 

 residue which fused to a white, porcelain-like mass. 



Analyses of worm tubes. 



Tests for fluorine failed to show its presence in any of these tubes. 



These analyses fall into two distinct groups, one low in sulphates and phosphates, the 

 other unusually high. The first three are easily reducible to standard form if we reject the 

 insoluble matter, the silica, and the sesquioxides, which represent inclusions of sand or mud. 

 The reduced analyses then assume the following form : 



Reduced analyses 0/ worm tubes. 



" Lenox, L. R., Harvard Coll. Mus. Comp. Zool. Bull., vol. «, p. 264, 1904. 

 106135—22 2 



> Damour, A., Compt. Rend., vol. 32, p. 253, 1851. 



