136 



THREE CRUISES OF THE " BLAKE. 



was dredged from 1 ,240 fathoms, over 300 fathoms deeper than 

 the greatest depth at which any plumularian was collected by 

 the " Challenger." The Tubularians, so common in shallow 



O 7 



water, do not seem to extend to any considerable depths. A 

 characteristic plumularian is the stately Aglaophenia bispinosa 

 (Fig. 431), dredged off Alligator and Tennessee reefs, from 

 200 fathoms, surpassed in size by very few hydroids. The cor- 

 bulse (Fig. 432) are very beautiful, and present a most instruc- 

 tive illustration of the morphology of the organ. The lower 



Fig. 432. Aglaophenia bispinosa, magnified. (Allman.) 



part of the stem is composed of tubes, which, at rather regu- 

 lar intervals, become curiously contorted into knob-like projec- 

 tions. (Fig. 433.) They become separated at the extreme lower 

 end, where they form a large entangled mass of filaments. 



Cryptolaria conferta (Fig. 434), forming crowded entangled 

 tufts, was dredged off Cojima, Cuba, in 450 fathoms. On the 



Fig. 435. Cryptolaria conferta, 

 magnified. (Allman.) 



Fig. 434. Cryptolaria conferta. 

 1. (Allman.) 



branches of one of the specimens occurred here and there ir- 

 regularly fusiform shaped bodies (Fig. 435), the nature of which 



