AT THE LOYALTY ISLANDS AND NEW BRITAIN. 157 



this definition still holds, the structures are not hooks. They are rather of the shape 

 of a roll of paper so folded as to form a half cylinder rather rounded at both ends. 

 Their presence serves to distinguish this species from others of the same genus, but 

 they should no longer be termed "hooks." 



This species is recorded in Selenka's Monograph, from Sydney, the Philippines, 

 Fiji and Amboyna. 



17. Sipunculus billitonensis Sluiter. (XIII.) 



Numerous specimens from Lifu, Loyalty Islands. 



Dr Willey's specimens were somewhat shorter than those described by Sluiter, none 

 of them surpassed 18 — 20 cms. in length, but in other respects they correspond well 

 with the description given of the type. As Sluiter has not figured the outside, I 

 have done so (Fig. 6). The anus is very prominent, ridged and ribbed (Fig. 7). 



18. Sipunculus cwmanensis Keferstein. (III.) 



Three specimens varying in length from :5"> cm. to 12 cm. from Uvea, Loyalty 

 Islands. 



I am inclined to think that these specimens belong to the variety S. cwmanensis 

 opacus Sel. and Billow, which is recorded from Mauritius and Ascension. The species 

 is widely spread and has been found off Venezuela, and Ascension, in the Red Sea, off 

 Mozambique and the Philippines. 



The characteristic transverse dissepiments which stretch across the body on the 

 inside of the skin were, in the specimen I opened, much more prominent in the posterior 

 third of the body than in the anterior two-thirds. The numerous diverticula of the 

 heart are very definitely arranged in two lateral rows. 



Some specimens of the variety S. cumanensis vitreus Sel. and Billow were gathered 

 at Blanche Bay, New Britain, and one example at the Isle du Phare, Noumea. The 

 circular muscles of these specimens were very violently contracted, and gave the outline 

 of some examples a very extraordinary appearance (Fig. 8). One of this variety attained 

 a length of 20 cm. 



19. Sipunculus edulis Lamarck. (VI.) 



Numerous specimens from Lifu, Loyalty Islands, and five from Gavutu near Florida, 

 one of the Solomon Islands. 



None of the specimens were, in the retracted state, longer than 12 cms., and were 

 thus shorter than Sluiter's specimens from Reede Batavia, Tandjong Priok which 

 measured 15 to 18 cms. (XII and XIII). But the Lifu specimens may have been young 

 or the Malay specimens may have been extended. 



The colour of the examples from Lifu was darker than Sluiter mentions and the 

 circular muscles are divided into fine bundles, but in other respects the animals corre- 

 sponded with his description. Dr Willey tells me that he thinks the specimens have 

 darkened in spirit, and this is undoubtedly the case in some specimens of Balano- 

 glossus— though not in all — that he brought home. The five examples from the Solomon 



