304 MR. CYRIL CROSSLAND OX THE [Feb. 16, 



a most important addition to my collection, since several species 

 of all these groups wei-e here met with for the first time. Some 

 time later I came across specimens of this species at low spring- 

 tide on the west shore of Puopo Islet, Kokotoni Harbour, 

 Zanzibar. Here the tubes were attached at their bases to the 

 ilat rock, and were stiff enough to stand vertically upright even 

 when the water had left them. Tubes were also dredged in 

 Wasin Harbour, whence also come three much younger speci- 

 mens, which show important differences from the full-grown ones 

 previously collected. 



The openings of the tubes are arranged more or less alternately 

 on either side as in E. tihiana Ehl., but are less numerous and 

 the tubes are sti-aighter. The basal part of the tube is very like 

 the fragment figured by Ehlers {I. c. Taf. 22. fig. 1), which shows 

 well their charactei'istic texture and surface. Although the tube- 

 wall is not thicker than ordinary brown paper and is free from 

 foreign material, it is perfectly opaque and so tough and elastic 

 that the tubes are cut or torn open with some diificulty. 



The colour of the animal in life is uniformly blood-red, except 

 towards the hind end, where the body becomes blackish. 



The head is broad and the peristomial segment, as usual, 

 cylindrical (PI. XXI. fig. 1), but immediately behind this the body 

 flattens ventrally, and a little later dorsally also, becoming in 

 section a narrow rectangle. A slight increase in breadth takes 

 place for a centimetre or two behind the head, after which the 

 body is parallel-sided for the greater part of its length, becoming 

 narrower and more cylindrical towards the tail. The diagram- 

 matic sections explain these changes (text-fig. 52). The segments 

 are very shoi-t throughout, though the six following the head are 

 longer than the rest (see fig. 1, PI. XXI.). 



Text-fig. 52. 



h. c. d 



X 2. 



Diagrammatic sections of boclj' of E. iuhifex, sp. n. 



a. Just behind buccal segment. 



h. In region of glandular feet, i. e. about 21tb segment. 



c. In tlie branchial region. 



d. Near hind end of bodj-. 



The pi'ostomium (PI. XXI. fig. 1) is short and broad, deeply 

 notched in front and covered by the anterior edge of the buccal 

 segment behind. The short and thick tentacles are indistinctly 

 ringed and have each a small thickened basal portion. The 

 middle one is about twice as long as the prostomium, the next 



