which, in contrast to the plates of Mazocraeidae, are strongly dismembered 

 and serve nnainly as the supporting apparatus of the suckers. The three 

 species of this genus for which larvae are known are: D. luscae (Beneden 

 and Hesse), D. poUachii (Beneden and Hesse), and D. denticulata (Olsson). 

 The larvae of the first two species were studied by Gallien (Gailien, 1934a), 

 but it is we who obtained the last one from the eggs which were brought to 

 us alive by A. V. Gussew and U. I. Polianski from the Norwegian Sea. 

 The eggs of D. denticulata were gathered by them from parasites from 

 the gills of the Pollack- -Pollachius virens (L. ). 



Upon ennergence from the eggs the larva of Diclidophora 

 (Fig. 226) swim freely with the help of the ciliary epithelium which is 

 located just as it is among the Mazocraes with a break at the level of 



£.1mm 



001mm 



Fig. 226. Diclidophora denticulata 

 (Olsson), free-swimming larva. 



Fig. 227. Diclidophora denticulata 

 (Olsson), attaching armature of the 

 free -swimming larva. 



attaching disc. The dorsoventrally flattened larvae are transparent. 

 The length of the larvae of D. luscae (Beneden and Hesse) in average 

 contraction is 0. 195 mm, its width is 0. 08 mm. The sizes of the larva of 

 D. poUachii (Beneden and Hesse) are not indicated by Gallien, just as 

 the other data, as a matter of fact, for he writes only about this larva 

 that it completely similar to D. luscae (Beneden and Hesse). The length 

 of the larva of D. denticulata (Olsson) is about 0. 35 mm whereas the 

 width is 0. 15 mm. At the level of the beginning of the posterior quarter p. 199 

 of the body of the larva, the attaching disc begins, which occupies in 

 length one-half of this quarter; the second half forms a powerful cone- 

 shaped growth. The larvae of all species are devoid of eyes. Their 

 pharynx is rounded and extends into a strongly developed sac -like intestine 

 which sonnetimes extends posteriorly into the attaching disc. The 

 excretory and other systems of organs were not discovered. The attaching 

 armature consists of 12 hooks of the same type as among Mazocraes 

 (Fig. 227); 10 edge hooks of approximately the same length and 2 larger 



216 



