SIPUNCULOIDEA 



429 





adhesive papillae found on their posterior end. Ph. strombi 

 fills its shell with mud, which must be kept together by some 

 secretion of the animal. The body lies in a tube in this mud, 

 and the introvert projects from the small round opening at the 

 end of the tube, and explores the ground in every direction. They 

 are found in all seas, but more especially in the colder waters. 



The genus Aspidosiphon includes nineteen species, which are, 

 with few exceptions, exclusively confined to the Indian Ocean 

 and neighbouring seas, including the Eecl Sea. The exceptions 

 are A. armatus from the Norwegian coast, and A. millleri from 

 the Mediterranean and Adriatic. A. truncatus is also stated to 

 occur at Panama, the Bahamas, and at Mauritius. The remain- 

 ing species almost all occur in the 

 Malay Archipelago and neighbouring 

 islands, and as was the case with 

 Phymosoma, this part of the world 

 seems to be the headquarters of the 

 genus. A. millleri lives in the inter- 

 stices of rocks and stones, and occa- 

 sionally in disused Mollusc shells. 



Two species of Aspidosiphon have 

 been described by Bouvier 1 living in 

 a state of commensalism with two 

 species of Madreporarian corals, Stepha- 

 noceris rousseaui and Heteropsammia 

 cochlea, which live on and surrounding 

 the shells of certain Molluscs at Aden 

 (Fig. 216). Apparently the Gephyrean 

 takes up its abode within its house 

 at a tender age, and according to Bou- 

 vier, it provides for its increasing bulk 

 by secreting a coiled calcareous tube, 

 the outer surface of which affords 

 space for the growth of the coral. 



The genus Cloeosiphon, the PJchino- 

 sipho7i of Sluiter, includes three 

 species: C. aspergillum (Fig. 217), C. 

 molle, and C. javanicum. The first named occurs at Mauritius, 

 the Malay Archipelago, and neighbouring islands ; the others are 

 1 Ann. Sci. nat. (7) vol. xx. 1895, p. 1. 



Fig. 217. Cloeosiphon aspergillum 

 Quatr. x ^. a, Introvert covered 

 with spines and partially ex- 

 tended, but not sufficiently to 

 show the head ; b, calcareous 

 plates surrounding the point of 

 origin of the introvert. 





