GEPHYREA. 175 



Sipuuculus, sp. 



A fragment of a Sipuuculus, which was insufficient to allow of identification, was 

 taken at Stn. LVL, south of Dutch Modragam Paar; depth, 8-9 fathoms, 



ECHIUKOIDEA. 



Bonellia pumicea, Sltjit. 



The only Echiuroid in the collection was a Bonellia, from Galle, which I rather 

 douhtfully identify with Sluiter's Bonellia pumicea (' Natuurk. Tijdschr. v. Nederl. 

 Ind.,' vol. 50, 1890, p. 111). 



EXPLANATION OF PLATE I. 



Figs. 1, 2, 3, 11, and 12 are of Aspridosiphon corallicola; figs. 4-10, inclusive, are of 



Centrosiphon herdmani. 



Fig. 1. .Side view of Aspidosiphon corallicola, Shut, x 10. The introvert is extended, but not quite to 



its full extent. 

 View of anus of the same species, with the thickenings of the anterior shield sloping away 



from it. 

 View of head of the same species showing the ring of tentacles. 

 Side view of Centrosiphon herdmani, n. g. et sp., with the introvert slightly extended from the 



anterior shield, x 8. The chestnut-coloured patches seen on one of the specimens are 



well shown here. 

 A view of the anterior plate and introvert of the same specimen seen from above, x 8. 

 A view of the posterior plate of the same specimen seen from below, x 8. 

 A transverse section through one of the papilla? around the base of the head of the same species 



showing the chitinous thickening. Highly magnified. 

 Fig. 8. View of the anterior end of the same species, cut open so as to expose the viscera, x 1C 



a., position of anus; d.r., the short, slender dorsal retractor muscles; o\, oesophagus ; 



;/./., genital ridge at the base of the ventral retractor muscles; ., nephridia ; n.c, ventral 



nerve cord ; ?., rectum ; vs., ventral retractor muscles. 



