64 



Gen. 11. Ascidicola, Thorell, 1859. 



Syn: Coeliacola, Hesse. 



Generic Characters. Body of female slender, vermiform, with no sharp 

 demarcation between the anterior and posterior divisions. Head well defined 

 from trunk and terminating in a broad rostral plate. The last 2 trunkal seg- 

 ments in female not coalesced. Tail composed in both sexes of 4 segments. 

 Caudal rami simple, not clawed at the end. Anterior antennae short and thick, 

 alike in both sexes. Posterior antennae more slender and. distinctly prehensile. 

 Oral parts poorly developed and rather differing in structure from those in the 

 other Notodelphyoida. The 4 anterior pairs of legs in female only adapted 

 for crawling, the rami being very short, biarticulate, the inner one armed at 

 the end with exceedingly long and slender spines; those in male of quite 

 normal appearance and well adapted for swimming. Last pair of legs in female 

 transformed to large lamellae encompassing the genital region of the body, 

 those in male very small and rudimentary. Ripe ova accumulated in 2 juxta- 

 posed ovisacs appended to the dorsal face of the body and arched over by 

 the transformed last pair of legs. 



Remarks. The present genus comprises as yet only a single species, to 

 be described below. 



21. Ascidicola rosea, Thorell. 



(PI. XXXI) 



Ascidicola rosea, Thorell, 1. c. p. 59, PI. IX & X, 13. 

 Syn; Coeliacola setigera, Hesse. 



Specific Characters. Female. Body almost perfectly cylindrical in form, 

 the anterior division being very little broader than the posterior. Head 

 slightly contracted in front, and terminating in a broadly rounded rostral plate. 

 The first 2 trunkal segments imperfectly separated, the 2 succeeding ones 

 however well defined. Last trunkal segment not clearly defined from the 1st 

 caudal segment, both having the dorsal face somewhat hollowed to make an 

 underlayer for the ovisacs. Tail very fully developed, exceeding in length the 

 anterior division, and composed of 4 well defined segments gradually some- 

 what diminishing in size, the penultimate one having the ventral part of the 

 hind edge remarkably thickened and densely clothed with small pricks, last 

 segment transversely truncated at the end. Caudal rami a little shorter 

 than the anal segment, and narrow linear in form, tip somewhat obliquely 



