Benham. — The Sipunculids of New Zealajid. 179 



The tentacles are, in the specimens studied, pale — no 

 doubt white in life — but the furrows in the oral disc and the 

 lobes, &c., are purplish; and in one individual examined each 

 tentacle is marked with one or two linear dots of the same 

 colour. 



Dimensions. — The average size of the body is about 

 25 mm., but it varies considerably. The specimen from Auck- 

 land has fully extended introvert and tentacles, as will be 

 seen from the following table : — 



Dimensions in Millimetres. 



Auckland. 



Rangitoto. 



Warrington. 



(a.) 



(6.) 



(c.) 



Cape 

 Campbell. 



Length of body 



Greatest diameter of body . . 



Diameter anteriorly 



Length of introvert 



Greatest diameter of introvert 



32 

 8 

 3 



Specimen (c) is thus nearly spherical. 



while several from Waiheke are much smaller than any of 

 these. This difference in many cases is due to differences in 

 condition of preservation. 



Internal Anatomy. — The longitudinal muscles form a con- 

 tinuous sheath. There are two large retractor muscles to the 

 introvert, which are inserted into the body rather far back — 

 at about one-third from the hinder end. The spiral intestine 

 exhibits about 8 double coils. The spindle muscle is attached 

 anteriorly only, so that the intestinal spire is free posteriorly. 



The vascular system is provided with numerous caeca, 

 resembling the figures given by Shipley for Physcosoma ivel- 

 donii.''' There is a pair of free " brown tubes," each of which 

 is dilated spherically at the external aperture ; and there is 

 no forward caecum. Several of the worms examined are 

 sexually mature. 



Localities. — Cape Campbell, South Island: Hutton's 

 specimen (h). Auckland: Collected by Professor A. P. 

 Thomas and Mr. H. Suter. Kangitoto, in Auckland Harbour : 

 Collected by Mr. H. Suter. Waiheke, in Auckland Harbour : 

 Collected by Dr. Agnes Kelly. Warrington, South Island : 

 Collected by W. B. Benham. 



Eemarks. 

 The scanty literature at my disposal does not permit me 

 to make comparisons with other species of sipunculids, or. 



•Q.J.M.Sc, 1891. 



