HOLOTHURIOIDEA :^89 



II. Family Stichopodid.e 



Tentacle ampullae present. Gonads on both sides of the dorsal 

 mesentery. Respiratory trees usually connected with the alimen- 

 tary canal through a rete mirabile. Stone canal usually connected 

 Avith the body wall. No Cuvierian organs. Deposits tables and 

 derivatives of pointed rods ; often C-shaped spicules ; rarely 

 buttons may occur. 



One genus known from the British and X.E. Atlantic seas. 



1. Stichopus Brandt. 

 (Syn. Parastichopus H. L. Clark. i) 



Body cylindrical or with ventral side more or less flattened, 

 with numerous tube-feet ; dorsal side vaulted, with papillae. 

 Twenty tentacles. Deposits tables ; C-shaped bodies may be 

 present, rarely also buttons ; no minute granules. 



Two species known from the British seas and from the N.E. 

 Atlantic. 



Key to the British and X.E. Atlantic species of Stichopus. 

 Body nearly cylindrical ; colour in life red. Besides the disks also 

 numerous star-shaped spicules present 1. St. tremulus (Gunn.) 

 Body flattened ; colour in life brownish with white spots. Star- 

 shaped spicules less numerous, and chiefly in the radii 



2. St. regalis (Cuvier) 



1. Stichopus tremulus (Gunnerus). (Fig. 228, 1.) 



(SjTi. Holothuria tremula Gunnerus ; H. elegans 0. Fr. Miill. ; 



H. ecalcarea M. Sars ; Stichopus Grieg i Ostergren ; Stichopus 



Richardi Herouard ; Parastichopus tremulus (Gunn.) H. L. 

 Clark.) 



Body nearly cylindrical, attenuating towards the ends. Mouth 

 sub ventral. The circle of tentacles surrounded by a fringe formed 

 by the anterior papillae, which are united by a web. Tube -feet 

 of the mid- ventral ambulacrum small, rather sparse and scattered ; 

 in the lateral ambulacra more crowded, larger, more papilla-like, 

 passing gradually into the papillae on the sides of the body ; the 

 papillae of the dorsal side again smaller. Calcareous deposits 

 (Fig. 231) very numerous ; disks of tables with serrate edge, rods 

 of the spire connected by 2 sets of cross beams. In the deeper 



^ The genus Parastichopus established by H. L. Clark for St. tremidus 

 does not seem sufficiently warranted, at least for the present. 



