1894.] MICROSCOPICAL JOURNAL. 381 



same organisms expressed in terms of the standard unit. 

 The dotted line represents the " suspended albuminoid 

 ammonia" in parts per 100,000. It will be noticed that 

 there is a general parallelism between the profile of the 

 albuminoid ammonia and that of the organisms expressed 

 in terms of the standard unit. This parallelism is what 

 ought to be found, because the suspended albuminoid 

 ammonia is supposed to represent that part of the nitro- 

 genous matter present as organisms or fragments of liv- 

 ing of dead matter, held in suspension in the water. It 

 will also be noticed that the curve of organisms plotted 

 according to the actual numbers, does not correspond 

 well with the chemical analyses. 



In conclusion it may be stated that this volumetric 

 method has been used in the Biological Laboratory of 

 the Boston Water Works since Jan. 1, 1893'^^, and has 

 given excellent satisfaction. It is also in use in the Bio- 

 logical Laboratory of the Lynn Water Works, and sev- 

 eral biologists in other laboratories have signified their 

 intention of adopting it. 



Classification of the Radiolaria ; Key to the Species of 

 Barbadoes. 



By REV. FRED'K B. CARTER, 



MONTCLAIR, N. J. 



This Key has been constructed from the descriptions 

 of the species of Barbadoes which are scattered through- 

 out the two huge volumes of text of Haeckel's great work 

 on the Radiolaria. 



1. UENOSPHJERA. 



Pores circular, with hexagoaal frames, 14-16 on the quadrant melecta. 



Pores irregular, roundish, 30-40 on the quadrant gigantea. 



2. ETHMOSPHiERA. 



Pores prolonged into conical tubuli, 16-18 on the quadrant polysiphonia. 



*18tb Annual Beport, Boston Water Board, 1893, page 72. 



