New British Enchytrmds. By Rev. H. Friend. '■'>'■'< 



appeared so marked. Bretscher's description as given above is 

 exceedingly accurate for the British species. These organs 

 branch out immediately behind the pharynx and extend back 

 to the beginning of segment v., filling up almost all the 

 coelomic cavity of segment iv., and presenting a very striking 

 appearance (Plate XXVIII. fig. 3). There are three pairs of septal 

 glands in segments v -vii., the hindmost pair being, as is frequently 

 the case, the longest ; and by the side of this pair lies the first 

 pair of nephridia. 



The dorsal vessel I found in one instance to begin in seg- 

 ment xiii. There is no other allusion in the diagnosis given above 

 to the vascular system. I may therefore add that I have found 

 an enlarged blood-vessel in segment viii., which reminds one of 

 what occurs in certain species of water-worm, such, e.g., as 

 Limnodrilus. Further, there is a double commissure in the 3rd 

 segment (Plate XXVIII. fig. 2), but I have not worked out all the 

 details of the system. The ccelomic corpuscles are oval, blunt, 

 cigar-shaped, or circular. It often happens that these bodies 

 assume a globular or circular shape immediately on being set free, 

 though they may appear pointed when they are flowing about in 

 the ccelom. The intestine is covered with cells which have under 

 certain conditions a very oily appearance. The girdle extends 

 over segment xii. to the seta? of segment xiii., and is slightly more 

 cellular or glandular in structure than the other parts of the body. 



When one is examining the region around the girdle, eggs in 

 all stages of development may perhaps be in the field. Though 

 these look white to the naked eye they are opaque under the lens, 

 and may make it difficult for the observer at first to study the 

 details of the sexual organs. Large male pores are found on the 

 girdle segment where the ventral setas are wanting, connected with 

 which is a long and very narrow duct leading to the ampulla, 

 which is somewhat pear-shaped, about twice as long as broad, and 

 possessed of a brownish orifice. These organs are paired. 



I have not detected in our native species the thickenings or 

 copulation-glands of the nerve-chord in segments v. and vi. But 

 my experience teaches me that these are very variable, and their 

 meaning, permanence, and other details are not yet sufficiently 

 understood. The brain is well developed and somewhat rounded 

 behind. Only when extremely tense does it show any signs of 

 concavity, this being due to the lateral attachments. 



The nephridia are chiefly post-septal, but I have not observed 

 the duct. The only other point of importance relates to the 

 spermathecse (Plate XXVIII. fig. 3). These are such characteristic 

 organs that it is always necessary to give them careful study. 

 The presence or absence of diverticula may enable one instantly to 

 decide the species. In the Enchytrreids they are (with one or two 

 exceptions) always found in segment v., with their opening in the 



Dec. 20th, 1911 3 b 



