HOLOTHURIOIDEA 



431 



that species in the edge of the anchor plates, especially those of 



the anterior body end/ being serrate, while in bergensis the edge 



is always in the main smooth, only with 



some few serrations here and there, mainly 



in the lower part. Also the size of the 



anchors and their plates is slightly larger 



in Galliennii. 



Development unknown. 



The species is known with certainty 

 only from the Atlantic coasts of France, 

 from the littoral region. It appears here 

 in some places to exclude L. inhcerens. 



Fig. 263.— Anchor and 

 anchor plate of Lep- 

 tosynapta Galliennii. 

 xl55. 



[Leptosynapta decaria (Ostergren).] 

 (Fig. 262, 3.) 



Tentacles 10, with 2-4 pairs of digits 

 increasing in length distally ; unpaired terminal digit the longest. 

 Alimentary canal straight ; no muscular stomach. Two to 

 three Polian vesicles. Ciliated funnels rather large, scarce, in 

 a single series in left dorsal interradius. Calcareous ring with 10 

 pieces ; radialia perforated. Anchor usually narrower than anchor 

 plate. Six serrate holes round the central hole, the outermost 

 one usually a little larger than the others (Fig. 262, 3) ; some- 

 times 1-3 more small holes along the outer edge. Colour whitish. 

 Size, 1-5-5 cm. long by 1-5-3 mm. thick. Development unknown. 



Hitherto known only from the Trondhjem Fjord to the 

 Kattegat, in 40-70 m. depth. 



[Leptosynapta minuta (Becher).] (Fig. 262, 4.) 



Tentacles 10, simple, without digits. Alimentary canal 

 straight, simple. One Polian vessel ; only a single ciliated 

 funnel. Calcareous ring of 10 pieces, all of the same simple 

 dumbbell-shape ; radials not perforate. Anchor narrower than 

 the plate ; the latter with only 3 holes in the articular end, the 

 middle one very narrow, slit-like (contrary to the other species, 

 which have several small, irregularly arranged holes in the 

 articular end of the anchor plate). Besides the anchors and 

 plates also small plates with 4 holes. Quite transparent, without 



^ In the posterior end of the body the plates are more like those of 

 bergensis, with the edge in the main smooth. On the whole there is usually 

 a more or less conspicuous difference in Synaptids between the deposits of 

 the anterior and posterior ends of the body. (Cf. e.g. Labidoplax digitata 

 and Thomsoni.) 



