380 



CH.ETOPODA. 



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

 Oydippidce. Alciojxi Cantrainil Delle Ch., Naples. 



Fam. Tomopteridae (Gymnocqpa). Head well marked, two eyes, bind 

 prrcstomium, 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 setae. 

 Tomojtti'ris scolopendra Kef., Mediterranean. '. onisdformis 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 Comatiila. 

 They possess a soft and 

 ciliated skin, four pairs of 

 laterally placed suckers on 

 the ventral surface, and a 

 protrusible proboscis fur- 

 nished with papilla? at 

 their anterior end, also a 

 branched alimentary canal 

 which opens at the posterior 

 end of the body. On the 

 sides of the body are five 

 pairs of short parapodia, of 

 which each one bears a hook 

 (with one to three supple- 

 mentary hooks) as well as 



0> /fjf" \ \ ^ ^/ supporting setae. As a rule, 



double as many cirri or 



short wart-like protube- 

 rances are found on the 

 margin of the body. M. 

 glabrum, cirriferum F. S. 

 Lkt. 



D 



Ov 



Fio. 308. Sjiirorlit lieris (after Claparode). a. The 

 animal removed from its tube, strongly magnified ; 

 ft, tube ; T, tentacles ; I?c, brood-pouch with oper- 

 culum ; Dr, glands, Ov, ova ; Oe, oesophagus ; If, 

 stomach ; D, intestine. 



Sub-order 2. Seden- 

 taria = Tubicolae. * 

 With indistinctly sepa- 

 rated head and short, 

 usually not protrusible 

 proboscis, without jaws. 

 The branchite 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 (Arenicolidce). As a rule, however, 

 they are represented by numerous filiform tentacles and ten- 



* E. Claparedc, " Eecherchcs sur la structure dcs Annelides sedentairci). ' 

 Geneve, 1873. 



