16 THE BOTIFEKA. 



specimens agreed accurately with each other, as described above. In the open water 

 they swam swiftly ; and it was difficult to confine them even with the compressor ; for 

 they soon managed, by contraction and elongation, to wriggle themselves out of the 

 field of view. The Nais was from a pool at Walthamstow. Examining another Nais 

 from the same phial, I found a single Albertia in the intestine; in another, an egg of the 

 parasite was within the intestine, attached to a pellet of faecal matter, which pushed it 

 along. The opacity of the bowel prevented my seeing whether any matured parasites 

 were present or not in this case. P.H.G.] 



Length, T J inch ; diameter, ^ ff to TTT Vff inch. Habitat, Walthamstow (P.H.G.) : 

 entozoic. 



A. NAIDIS, Bous field, sp. nov. 

 (PI. XVII. fig. 14.) 



[SP. CH. Body moderately long, the cervical and pectoral parts the thickest, 

 diminishing to the hind part ; toe minute, soft, papilliform ; integument slightly con- 

 stricted in the hinder half. 



This species was discovered by Mr. Edward C. Bousfield, who has kindly communi- 

 cated to me his own careful drawings and descriptive MS. notes. He has "several times 

 observed it in situ, in Nats barbata, living free within the cavity of the stomach of its 

 host." 



"Body cylindrical, soft, hyaline, vermicular, extremely flexible and telescopic, espe- 

 cially the hinder part. Anterior extremity truncate. Trochal disc small, oblique, on 

 dorsal aspect of body. [One drawing shows that it is invertile, the cilia being depicted 

 far down the buccal funnel. P.H.G.] Jaws very minute, protrusile, snapping. Ali- 

 mentary canal conical, extending through the body, opening at the junction of the last 

 two segments. Gastric gland semi-ovoid. Ovary straight, slender, cylindro-conical ; 

 the ova developed serially. A minute contractile vesicle. 



" Caudal appendage [= foot, P.H.G.] papilliform, composed of two joints [of which 

 the terminal is] soft, resembling in its action the finger of an elephant's trunk." 



"Habitat. Vicinity of London. Anterior portion of stomach of Nats, in which it 

 moves freely. Egg about one-third of length of parent's body. Length, ^^ inch." l 

 P.H.G.] 



Genus TAPHROCAMPA, Gosse. 



[GEN. CH. ~BoA.y fusiform or cylindrical, annulose, furnished with two furcate toes; 

 trophi forcipate ; rotatory cilia wanting or very limited. 



T. ANNULOSA, Gosse. 

 (PL XVII. fig. 12.) 

 Taphrocantpa annulosa . . . Gosse, Ann. Nat. Hist. 2 Ser. 1851, p. 199. 



SP. CH. Body cylindrical, short and thick, marked throughout with distinct articu- 

 lations ; brain opaque; alimentary canal simple, wide, cylindrical; terminal fork 

 thick, conical, acute. 



This animal is very larva-like ; the body consists of many well-marked rings or 

 segments which are set within the clear cylindrical integument, apparently touching 

 this only at the points. Each of these, if viewed through the longitudinal line, would 

 be of a sub-square outline, with four projecting angles, as seen at fig. 12&. In general 

 no vortices are seen, nor any trace of vibratile cilia, so that I long concluded 



1 Thus the three recorded species differ notably in their respective dimensions : A. vermiculus 

 being -^ inch to ^ inch (Duj.) ; A. intrusor, 1 -i jJ in. (P.H.G.) ; A. na'idis, 5 f s in. (Bousfield). 



