BY E. F. HALLMAKK. 



471 



are much more fi^equently blunt-pointed — they are notably lar 

 180 to 370/x long and (at most) ll/z stout in the branches, 

 occasionally attaining to 510 x 17"5/;. in the stalk. 



Microsdercs. — (i.) The spirula; (Text- 

 tig. 3) are mostly of less than 2 turns, 

 rarely of more than 2^. Rod-shaped 

 derivatives of them, of all lengths be- 

 tween 4 and 23/a, and from 2 to 3"5/a 

 in diameter are fairly common — num- 

 bering, say, one to every forty or fifty 

 of the coiled spicules; the latter rarely 

 exceed 2"5/j( in diameter. 



ger, 

 and 



c^,^.^.- 





U 



Text-tig. 3. 



(ii.) The uiicrostrongyla are imper- 

 fectly differentiated into two kinds ; ( 1 ) 

 slenderer, invariably centrotylote forms 

 ranging in length from 12 to 27 /x and 

 ill diameter from less than \\i up to 3 

 t)r 3"5/jt, and (2) stouter, rarely centro- 

 tylote ones, occasionally as much as 

 o/x in diametei', and seldom more than 

 20 /x in length. The former are present 

 in great abundance in three of the ex- 

 amined specimens, but are almost, or 

 entii-ely absent from the fourth; the 

 latter are scarce in all four specimens. 



Text-Hg.4.t 



'%Spirula? and niicrostrongyla of Trnchydadw^ dir/lfafii-s. 

 t Tvachyi-hidva dinitatux. Megascleres : n, fiom the stalk; //, fiuin the 

 branches. 



