220 



THE VOYAGE OF H.M.S. CHALLENGER. 



The ovaria are ovate or subspherical, each with a single large ovum only, which is 

 often surrounded by an irregular net of spadicine canals (PL XV. fig. 15 ; PI. XVIII. 

 fig. 16). The spermaria are more oblong, spindle-shaped, cylindrical or club-shaped, with 

 a simple central spadix (PI. XV. fig. 14; PI. XVIII. fig. 17). 



Ontogeny. — The development of the fertilised egg and the peculiar metamorphosis of 

 the larva (Physonula) arising from it, is known only in a few Agalmidse. It was first 

 described by myself in 1869, in Crystallodes rigidum (84, Tab. vi.-xiii.) ; afterwards by 

 Metschnikoff, in 1874, in Halistemma rubrum, Cupulita picta, and Agalmo2)sis sarsii 

 (85, Taf. viii.-xii.), and finally by Fewkes in Agalmopsis elegans (89). 



I. Subfamily 



CRYSTALLODIN.E. 



Siphosome short and 

 rigid, about as 

 long as the nrscto- 

 some. Trunk of < 

 the siphosome 

 stiff, scarcely con- 

 tractile, densely 

 covered with thick 

 prismatic or sphe- 

 roidal bracts. 



II. Subfamily 



AnTHEMODINjE. 



Siphosome very long 

 and movable, 



much longer than 

 the nectosome. 

 Trunk of the 

 siphosome very 

 extensible and 

 contractile, loosely 

 covered with thin 

 scales or folia- 

 ceous bracts(rarely 

 with prismatic 

 bracts). 



Synopsis of the Genera of Agalmidse. 



Tentilla with a simple terminal filament, . 41. Stephanomia. 



42. Crystallodes. 



Cormidia ordinate. 

 Internodes free, 

 covered only with 

 bracts. Palpons « 

 and gonostyles at 

 the base of the 

 siphons. 



Tentilla tricornuate, with a triple terminal 

 filament, ...... 



Cormidia loose 

 Palpons and go 



Tentilla with a simple terminal filament, 



to the inter 1 Tentilla tricornuate, with a triple termiual 

 nodes, between mament ' • • • • • 



the siphons. [ 



Cormidia ordinate. 

 Internodes free, 

 covered only with 

 bracts. Palpons < 

 and gonostyles at 

 the base of the 

 sijjhons. 



Tentilla with a simple terminal filament, . 



Tentilla tricornuate, with a triple terminal 

 filament, ...... 



43. Phyllophysa. 



44. Agalma. 



45. Anthemodes. 



46. Cuneolaria. 



