!(!(') Mr. 11. N. Moscley on Pelagonemertcs Rollcstoni. 



reni.iiiieil an impcrfoct one, and tlie affinities of the animal 

 amongst other ^semcrtines coukl not be determined. 



The animal is leaf-like in sliape, narrowing to a blunt point 

 at the posterior extremity, and commencing abru])tly at the 

 anterior. The proboscis is protruded from the summit of a 

 protuberance occupying the middle region of the anterior 

 extremity. The mouth is situate on the ventral surface of 

 the body, just posterior to the aperture for the proboscis. 

 It is a simple aperture, witli a plaited margin composed of 

 five or six folds. It is the commencement of a short muscular 

 tube, the oesophagus, which was seen to pass behind tlie most 

 anterior prolongation of tlie main mesial digestive canal, but 

 the communication of which witli the latter was not traced. 

 The digestive system stands out very conspicuously in the 

 fresh condition of the animal, from being of the deep burnt- 

 sienna colour already mentioned. It consists of a broad, 

 flattened mesial canal, somewhat broadest in the middle region 

 of the body, anteriorly ending in a bluntly terminated caecal 

 prolongation, and posteriorly narrowing gradually. As the 

 posterior part of the animal was somewhat injured, it could 

 not be determined whether the canal terminates in an anus 

 or not. 



The mesial canal receives on either side lateral tributaries 

 in pairs, which tributaries remain simple for some distance of 

 their horizontal course and then break up into ramifications. 

 The most anterior pair of lateral canals is split up into by far 

 the most ramifications. The ramifications become less and 

 less in each pair towards the posterior extremity of the body, 

 some of the most posterior lateral canals being simply bi- 

 furcate, and one merely enlarged at the extremity. There 

 are thirteen pairs of lateral canals in all. 



The nervous system was plainly seen in part. A pair of 

 rounded ganglia lie on tlie ventral and lateral surface of the 

 sheath of the proboscis, being a little posterior in position 

 to the mouth. A commissure passes above the oesophagus and 

 between it and the proboscis-sheath. From the ganglia a 

 pair of fine simple nerve-cords pass in a curved course dow^n 

 to the posterior extremity, where their termination could not 

 be ascertained. The cords cross ventrally the lateral digestive 

 canals about the point where ramification commences. Further 

 connexions of the ganglia could not be ascertained. 



The specimen obtained w^is a female. A series W ovaries, 

 consisting of pear-shaped masses of minute ova, were present, 

 situate between each of the pairs of lateral digestive tubes, 

 immediately external to the nerve-cord on each side. The 

 masses of ova are contained in >mall cavities in the gelatinoiuj 



