32 MR. W. F. LANX'HESTER ON THE [Jan. 17, 



Loc. British East Africa, 10 fathoms; 2 specimens, small. 

 Chwaka, Zanzibar ; 2 specimens, large. 



These incli^"icluals evidently correspond with a form described 

 by Selenka from the Red Sea, which differed from the type in the 

 following particulars : the papilla? on the hind end were a little 

 shorter and thicker, the hooks a little shorter, and the venti'al 

 retractors tending to be inserted a little more posteriorly. Selenka 

 was unwilling to establish a variety on a single specimen, but it 

 would seem better, now that we have these additions, to distin- 

 guish the form as a variety. The papilL'^ on the introvert are 

 exactly similar to those on the hind end of the bodj^ ; but even 

 shorter and broader. I figure these, and one of the hooks 

 (v. figs. 2 «, 2 h). 



12. Phascolosoma glaucum, sp. nov. (Plate I. fig. 8.) 



Loc. Zanzibar Channel, 10-15 fathoms. 



In this species, which is represented by a single specimen, there 

 are no hooks, and only two retractors. The muscle-laj-ers are so 

 loosely attached to the skin that they readily tear away from it 

 on opening the animal ; the retractors themselves arise, as strands 

 ob^'iously split off from the longitudinal layer of the muscle- 

 system, from the anteiior border of the hinder Cjuaiter of the body, 

 and meet each other round the oesophagus at the level of the 

 base of the introvert. The body is 13 mm. (approximately) in 

 length, the introvert 5 mm. only ; the latter has a slightly darker 

 tinge, owing to the crowding together of the pigmented papillate 

 bodies, which are very low and not visible to the unaided eye, 

 but distinctly so with the lens, under which they appear as distinct 

 black spots. The papillae on the body are visible under the lens 

 as distinct clear spots ; under the microscope they appear as 

 elongated bodies with a clear apical opening and carried on fields 

 roughly oblong in shape. 



Internally, we find the oesophagus running back wath the 

 retractors as far as their insertion, and then bending shai-ply 

 forward for a httle distance before entering the intestine ; the 

 latter contains about 16 spiral turns, and is not attached to the 

 hmd end of the body. The rectum is without a diverticulum, 

 and opens by the anus just behind the level of the base of the 

 introvert. Two muscle-strands suppoit the intestine anterioi'ly, 

 and two more, arismg from close to the nerve-cord on each side 

 of it, support the oesophagus at the angle where it bends foi-wai'd. 

 Thei'e is a contractile vessel, thickly beset with little diverticula, 

 along the length of the oesophagus where it lies between the 

 retractors. The nephiidia are colourless, and open just in fi'ont 

 of the level of the anus. 



13. Phascolosoma wasini, sp. nov. (Plate I. fig. 4.) 



Loc. Wasiu, British East Africa; 10 fathoms. 

 Six specimens, of which the largest is 15 mm. in length. The 

 most characteristic feature of this species is the laumei-ous rows of 



