Manchester Memoirs, Vol. xlvii. (1903), No. 5. 5 



Colour (no note on the living animal) white, with a 

 small number of scattered brownish spots, due to the 

 presence of dorsal pigment containing gut diverticula of 

 the same character as those which I have elsewhere 

 described for Planocera arinata [8]. 



Eye-spots in two thick clusters, one at the base of 

 either tentacle, and in four groups of brain-eyes, two on 

 either side of the middle line between the tentacles. The 

 hinder pair of these consist of but few spots ; the anterior 

 pair are each of them, roughly, an elongated band of eye- 

 spots, extending in front of the tentacles. In addition to 

 the eye-spotsand the pigmented diverticula already referred 

 to, there is a 'cloud' of minute black spots collected in 

 the mid-dorsal region, especially over the pharynx. A 

 similar feature was observed in P. iangii. 



Male Organs. The prostate and penis lie within the 

 outer muscular sheath. The prostate, which is a large, 

 roughly spherical gland, very similar to that of other 

 species, occupies the upper proximal end of the sheath, and 

 communicates by a muscular, rather thick-walled duct 

 with the penis, which receives the duct at its proximal end 

 on the ventral surface. The penis is a coiled muscular 

 tube; at its distal end its walls become continuous with 

 the outer sheath. Its lumen is lined with small, rather 

 widely separated spines, which increase in size as the 

 antrum is approached. This layer of chitinous spines is 

 interrupted at about the middle of the length of the penis 

 by large folds of the wall coated with a thin layer of chitin. 

 These folds have caused tearing of the sections, and 

 consequently it is not possible to describe their exact 

 arrangement. They are precisely similar in character to 

 the folds described in the penis of P. Iangii. The antrum 

 masculinum is very small, lined with secretory epithelium. 



Immediately after it leaves the prostate, the duct 



