Alien Oligochsets in England. By Rev, H. Friend. 155 



worm preserved in alcohol they can be seen behind the girdle as a 

 pair of large white convoluted bodies. In section some portions 

 have an appearance which recalls the " flames " in the nephridia of 

 Enchytrffiids. 



The alimentary system presents several points of interest. 

 The intestine widens greatly in segment 12 (fig. 2, int.e.). 

 Attached to the ventral side of the oesophagus in the 9th segment 

 is a pair of glands which in structure exactly resemble those of 

 Hcnlea fragilis Friend (.^). The illustrations (figs. 2 and 4) 

 show them to be securely attached to the posterior surface of the 

 strengthened intersegmental septum 8/9. These organs were 

 known to Beddard as " calciferous pouches," but Michaelsen 

 designates them "Chylustaschen." They are pear-shaped, and open 

 directly into the oesophagus. There is no trace of the " nephridial 

 element" here, which has been doubtfully recorded for some other 

 species. There is also no gizzard. 



The se2:)ta, or mesenteries, in some of the anterior segments, as 

 is very frequently the case, are thickened. This applies in a 

 marked degree to 6/7, 7/8, and 8/9, and in a lesser measure to 

 4/5, 5/6, and 9/10. Some of these septa are displaced, being thrust 

 back so much that later septa become greatly crowded. The septal 

 glands extend between the 4th and 8th segments, their maximum 

 development being dorsal in segments 5, 6 (fig. 1, sep.glX 



The nervous system does not require any special attention. The 

 shape of the brain could not be seen in the living worm, l)ut its 

 contour has been reconstructed b}^ means of a series of longitudinal 

 vertical sections (fig. 5). I have not found it possible to give 

 a detailed account of the vascular system. Sections, however, 

 seem to indicate the 11th segment as the one in which the blood- 

 vessels assume their largest development (fig. 2, h.v.). 



V. — Eelative Position of Kerria rubra. 



The various species of Kerria may be arranged according as 

 they have or have not diverticula to the spermathecte, double or 

 single prostates, copulation papilhe, one or two pairs of spernia- 

 thecfe, pigment in the body-wall, and a rudimentary or fully- 

 developed gizzard, as against the absence of a gizzard, and the 

 existence or otherwise of ovisacs, as well as by sundry other 

 features. 



As we have seen, Kerria rubra possesses no diverticula to the 

 two pairs of spermathecse. The prostates are not doubled, and 

 there is no gizzard, but an ovisac is present, and the creature is 

 red. If, now, we tabulate the characters of those species of Kerria 

 which show these peculiarities, we shall be able to judge which of 



