43() 



EOHINODERMS OF THE BRITISH ISLES 



more like those of digitata, but the handle is shorter and broader 

 and with more holes. No giant anchors arc found. Colour and 

 size as in L. digitata. 



In British seas this species is known only from the locality 



Fig. 267. — Anchor plates {a-c) and anchors {d) of Labidoplax Thomsoni. 

 X 100. (After Koehler, J&chinodermes, Faune de France.) 



a, From the anterior part of body ; b, from about the anterior fourth part ; 

 c, from the middle and the posterior part of body. 



where Herapath got his original specimen, viz., Carrickfergus, 

 on the Antrim shore of Belfast Lough. That it will prove 

 to have a wider distribution along the south and west coasts 

 cannot be doubted. It is known elsewhere from the Atlantic 

 coasts of France and from the Mediterranean, occurring together 

 with L. digitata. 



[Rhabdomolgus Kef ers tein . ] 



Calcareous deposits absent. Tentacles 10, simple, finger- 

 shaped. 



Only one species known. ^ 



Rhabdomolgus ruber Keferstein. (Fig. 268.) 



Alimentary canal straight ; no muscular stomach. One Polian 

 vesicle, I stone canal ; no ciliated funnels. Gonads only a single, 

 sac-shaped, imbranched tube. Genital opening behind the dorsal 

 tentacles. Calcareous ring consisting of 10 dumbbell-shaped 

 pieces. Colour intense red. Does not exceed ca. 1 cm. length. 



Lives on rather coarse sand, apparently not buried in the 



^ The Rhahdoynolgus novce-zealandice Dandy and Hindle does not really 

 belong to this genus. 



