S4 ox THE OEPHYIiEAX WOKMS OF ZAXXIBAU. ETC. [Jan. 17, 



16. AspiDosiPHON thuxcatus, Kef. 



Selenka, torn. cit. p: 118 (1883); Sluiter, Siboga-Exp. p. 17 

 - (1902). 



Loc. Wasin, British East Africa ; 10 fathoms. One very 

 small specimen. 



ECHIURIDA. 



Yl. Genus Thalassema. 



17. TuALASSEMA BARoXii GreefF. 



GreeflT, Die Echiuren, Nov. Act. Acad. N. Cur. xli. p. 151, 

 pi. vi. fig. 64 (1879). 



Loc. Zanzibar Channel. 



Hah. Shore, above lowest tide-level. 



The anal trees appear simple and not dendritic in this single 

 specimen, as they do also in at least two among those collected by 

 Dr. Willey. This character, together with the lack of any traces 

 of the nephridia (which I cannot find either in this or in one of 

 Dr. Willey's specimens), I take to be due to the fact that the 

 individuals in question may be young. There is also a small 

 globular diverticulum on the dorsal side of the rectum in this 

 species. 



Mr. Crossland has a note on the colour of this specimen to the 

 following effect : " Crimson-lake colour, with light-green pi-o- 

 boscis." Previous descriptions of the colours in this species give 

 them as being dark-green in the body with violet stripes. Evi- 

 dently, then, the col our- character is not necessarily constant, for, 

 despite the absence of nephridia, I feel no doubt as to the correct- 

 ness of my diagnosis on anatomical grounds, especially after 

 comparing them with the specimens from Dr. Willey's collection. 



18. Thalassema moebii Greeff. 



GreeflT, torn. cit. p. 152. 



Loc. Chwaka Bay, Kokotoni Bay. 



Hah. In sand in sheltered bays like the above. 



Two specimens, on which Mr. Crossland has the accompanying 

 note : — " Abundant in sheltered bays in sand above low-tide level, 

 but extremely difiicult to secure, as the burrows extend into 

 crevices in the rocks below the sand. The larger specimens I 

 never succeeded in obtaining. They occur with proboscides a foot 

 or more long " (tliis presumably refers to those of large size) " when 

 lying extended on the sand. Colour pink, owing to coslomic fluid 

 seen through skin. Proboscis cream-coloured and more opaque." 



19. Thalassema sp. ? 

 Loc. Chwaka, Zanzib.ar. 



A single specimen in a very bad state of preservation. It is 

 impossible to refer this specimen with any certainty to any knoAvn 



