Mr. II. N. Moselcy on Pelagonemertes Rollestoni. 1<J7 



internal body-tissue. Wlien pressure was exerted, tlie ova 

 issued from small corresponding apertures on the ventral 

 surface, and the small emjity cavities remained. The ova 

 were spherical, about "l'f'> millini. in diameter, and appeared 

 composed of fat-globules and granular matter. 



The proboscis-sheath, which is wide and ca|)acious, is very 

 plainly seen on the dorsal aspect of the body, and dimly 

 through the thickness of the body from the ventral aspect. 

 It has a firm muscular attachment at its orifice ; and bundles 

 of muscular fibres (apparently retractor) are attached to it here 

 on either side {PI. XV. B. fig. B, 1). The ])roboscis itself is, 

 when retracted, coiled up in the usual manner within its sheath, 

 as seen in fig. D. It could unfortunately not be ascertained 

 whether the proboscis is armed or not. It was never entirely 

 retracted ; but a small portion of it always remained exserted. 



The outer surface of the body of the Nemertine is covered 

 with a hyaline, very thin integument, which is thrown into 

 numerous folds and wrinkles, which are so aiTangcd along 

 certain lines around small spaces nearly free from them as 

 to produce on the surface of the body an appearance of a 

 series of small polygonal areas separated by fine reticular 

 network (fig. D ). This condition of the surface was most 

 conspicuous about the anterior part of the body ; but the 

 body was much lacerated by the meshes of the trawl, and 

 therefore I cannot say whether the whole integument is 

 in this condition in the fresh state or not. The folds and 

 plaits in the integument are so sharp that they give the ap- 

 pearance, under the microscope, of somewhat spindle-shaped 

 bodies with sharply pointed extremities (fig. C, 1, 2, 3). At 

 first I supposed that these bodies were urticating organs re- 

 sembling those of Bipalium ; but on carefully teasing up a 

 poi'tion of the integument with fine needles, and being unable 

 to isolate a single one, I concluded that they were mere folds. 

 They are, however, of remarkable appearance, from their ex- 

 treme abundance and the manner in which they cross each 

 other at all angles. They are well preserved in glycerine 

 preparations of the skin hardened in picric acid. 



Beneath the integument is some granular glandular matter. 

 Immediately beneath the integument, and in close adherence 

 to it, is the muscular tunic, evidently the homologue of the 

 cutaneous muscular system of Bipalium and other Planar ians. 

 As in these, the outermost fibres are circular in direction, the 

 inner longitudinal. 



The muscular tunic encloses tiie entire body. It is thin, 

 and in the fresh condition of the animal transparent and in- 

 conspicuous, but becomes oparpie when the animal is hardened 



12* 



