232 . P. W. GAMBLE, B.SC. 



widened. Flagellce appear to be absent. The rods are accumulated 

 in packets chiefly at the two extremities. Individual rhabdites are 

 longer at the anterior, shorter at the posterior end — exactly the 

 reverse of the case in A. hamatus, Jensen. Strong adhesive cells occur 

 on the "tail." The pharynx is placed about the commencement of 

 the posterior third. When extended the free end expands, the base 

 becoming constricted. The intestine, which contains pinkish granules, 

 is marked sacculated. The pouches numbered about twenty on each 

 side, and in compression-preparations appeared to be fairly definitely 

 paired. Between successive gut-sacs were muscular dissepiments. Ocular 

 pigment is absent. Testes occupy spaces in front and at the sides of 

 the pharynx. The vasa deferentia lead to a vesicida seminalis, and this 

 opens, along with the accessory glands, into the penis, a pyriform 

 muscular organ, similar in position and form to that of A. hamatus. 

 The pair of germaria lie at the base of the pharynx, the yolk-glands 

 accompanying the gut-pouches and lying between them. The oviducts 

 were not observed. 



Habitat. — Dredged in .twenty fms., Plymouth Sound (F, W. G.). 



Distribution. — Corfu (0. Schmidt). 



Schmidt's description of this species does not agree in all points with 

 the diagnosis just given of my own specimen. The differences consist 

 in the following details : the presence of ocular pigment in front of the 

 otolith, and the relations of the pharynx and ovaries. The latter, in 

 his specimen, occupied a position behind and not in front of, the 

 pharynx. The extreme contractility of the phai'ynx itself, and also 

 of the body-wall, cause, especially during compression, marked changes 

 in the position of the various organs. It is therefore possible that 

 Schmidt's figure (34, pi. iv, fig. 3) may not represent the natural 

 relations, v. Graff (53) does not mention the position of the ovaries, 

 upon which Schmidt laid stress. For the present, therefore, and until 

 more specimens are available, I place the Plymouth specimen under 

 Schmidt's species, with which in almost all other points it appears to 

 be identical. 



Sub-order 2 .— TRICLADIDA.* 



* This sketch of the two marine Triclads of our shores will at least serve 

 to show how much still remains to be done in the group. The synonymy is 

 very difficult, and requires a thorough revision. 



