380 



CH^TOPODA. 



its aperture are two hook-shaped papillae. The larvae are in part parasitic in the 

 Cydipplilce. Alciopa Cantrainil Delle Ch., Naples. 



Fam. Tomopteridae {Gynmocopa). Head well marked, two eyes, bifid 

 prffistomium, and four tentacles, of which two in many species are only present 

 in the young. The mouth segment has two long tentacular cirri which are 

 supported by a strong internal seta. The mouth is without proboscis and 

 jaws. The segments are provided with large bi-lobed parapodia without seise. 

 Tomojjteris scolopendra Kef., Mediterranean. T. onisciformls Esch., northern 

 seas, Heligoland. 



The genus Myzostoma F. S. Lkt., a small group of hermaphrodite worms 

 whose affinities are doubtful and disputed, may be placed here. They are 



small, disc-shaped animals, 

 parasitic on Comatula. 

 They possess a soft and 

 ciliated skin, four pairs of 

 laterally placed suckers on 

 the ventral surface, and a 

 protrusible proboscis fur- 

 nished with papilla3 at 

 their anterior end, also a 

 branched alimentary canal 

 which opens at the posterior 

 end of the body. On the 

 sides of the bod}- are five 

 pairs of short parapodia, of 

 which each one bears a hook 

 (with one to three supple- 

 mentary hooks) as well as 

 supporting setas. As a rule, 

 double as many cirri or 

 short wart-like protube- 

 rances are found on the 

 margin of the body. M. 

 glabrum, cirrifcrum F. S. 

 Lkt. 



Ov 



FIG. 308. Spirorli* l&i-ig (after Claparede). 

 animal removed from its tube, strongly magnified; 

 b, tube ; T, tentacles ; Bn, brood-pouch with oper- 



Sub-order 2. Seden- 

 taria = Tubicolae. * 

 The With indistinctly sepa- 

 rated head and short, 



culum; Dr, glands, Ov, ova; Oe, oesophagus; M, usually not protrusible 

 stomach ; D, intestine. proboscis, without jaws. 



The branchiae may be entirely absent and in many cases are 

 confined to the two or three anterior segments following the 

 head. In exceptional cases they are placed on the dorsal part 

 of the middle of the body (Armicolidce). As a rule, however, 

 they are represented by numerous filiform tentacles and teri- 



* E. Claparede, " Eecherches sur la structure des Annelides sedcntaires. ' 

 Geneve, 1873. 



