456 CLARK: BATHYMETRICAL DISTRIBUTION OF CRIXOIDS 



trolytes saved from inside the porous cups: this is the anode 

 liquid which should give too heavy a deposit, if Richard's theory 

 is correct. It was found, however, that if the electrolyte was 

 •om filter paper the deposit was perfectly normal. 



Many of the deposits were examined under the microscope, 

 and also photographed. From pure electrolytes, the deposits were 

 always crystalline and non-striated, and. indeed, the appearance 

 of the deposit was found to be a good criterion of the purity of 

 the electrolyte. 



It was found that to produce a heavy deposit, it was not nec- 

 essary to bring the electrolyte and filter paper together, but 

 merely to make up the electrolyte with water that had stood 

 over filter paper for a short time. It was evident that important 

 chemical changes were produced in the electrolyte by th filter 

 paper, and. accordingly. Dr. McDaniels joined us in the summer 

 of 1909 to study the chemistry of the voltameter. 



With the porous cup form, the authors obtained 1.01S2S7 volts 

 for the Weston normal cell at 20°, and this is very close to the 

 final result, which will be given in the last paper of the series. 



ZOOLOGY. — The occurrence of nodes in the bathy metrical dis- 

 tribution of the recent crinoids. Austin H. Clark. 



Among the recent crinoids the most important of the faunal ' 

 areas, the one to which all the other faunal areas are subsidiary 

 and of which they appear to be derivatives, has a somewhat 

 peculiar geographical distribution. From the Moluccas and the 

 Lesser Sunda Islands it extends eastward past Xew Guinea, 

 then southeastward to Xew Caledonia. Fiji. Samoa. Tonga and 

 the Kermadec Islands, near Xew Zealand: reappearing at Hawaii 

 it extends thence westward to southern Japan and southward 

 along the Kuril Islands to Formosa: westward from the Lesser 

 Sunda Islands it extends, by way of the Andarnans and Ceylon, 

 to the Mascarene Islands. Madagascar and southeastern Africa. 

 It has sent two very distinct branches into the Atlantic, a northern 

 and a southern: the former, from the Bay of Bengal, has spread 

 thruout the Mediterranean and along the east Atlantic Coa>t~ 

 from the Gulf of Guinea to Xorway: the latter, from southeastern 



