Alien OligocJtsets in England. By Bev. H. Friend. 267 



penial setpe, neither do the seta? near the male or female apertures 

 seem to be lacking as in D. damonu. 



Xcgativc Characters. — In my former paper it was observed that 

 a fuller account of the negative peculiarities of new worms would 

 often be of great service in diagnosis. The following points have 

 been observed in the present species. There is an absence of 

 pores on the dorsal region so far as the longitudinal sections 

 extend, i.e. from the head to the posterior girdle-segment. 

 Nephridia seem to be lacking until segment 12/13. There are no 

 thickened septa, no penial setre, no ccelomic corpuscles, and there 

 seems to be an entire absence of penial bulbs and prostate papilke. 

 The only swollen portion which I have been able to detect is 

 related to the female pore on the ventral surface of segment 14. 



Internal Characters. — The internal structure has been most 

 carefully studied by means of a complete series of longitudinal 

 sections extending from the prostomium to the girdle inclusive. 

 As already intimated, some of the sections are torn, owing to the 

 presence of grit in the intestine. In many sections also the septa 

 are either wanting or so congested that it takes a considerable 

 time before one can be quite positive in certain cases to which 

 segment a given organ is to be referred. By dint of frequent 

 drawing and repeated revision, howe\-er, all cdfficulties have been 

 overcome or reduced to unimportance. 



The sexual organs, because of their importance, demand our 

 first attention. The most advanced of these organs are the sper- 

 mathecfc. Of these there are two pairs (as in Kerria rubra) 

 opening in the inter-segments 7/8 and 8/9. They may be best 

 described perhaps as hour-glass or bottle- gourd shaped, and this 

 peculiarity has suggested the trivial name.* They are not attached 

 to the oesophagus, but lie free in the ccelom ; the foremost pair 

 being smaller than the posterior. What may be regarded as a 

 degenerate diverticulum is found on the anterior face of each 

 spermathecse. The spermatozoa, which I found here very sparsely, 

 were in the early stage of development, while those present in 

 the duct and ampulla were flagellate (fig. 18). In the duct there 

 seemed to be distinct evidence that the spermatozoa were held 

 together by a gelatinous cement. Although aliens in England, 

 these worms were evidently quite at home. They cannot, 1 am 

 told, have been imported in very recent years, but must have 

 bred in the house for a long time, and the duct and ampulla were 

 crowded with spermatozoa, showing that there had been inter- 

 course between the individuals. 



The testes are as usual situated in segments 10 and 11, where 

 also may be seen the funnels, staining deeply on account of the 



* Lageniformis, or having the shape of a flagon, hour-glass, or bottle-gourd. 

 From the word lageua, Kayrivos, a flagon, the term Lagenaria has been derived. 

 This is the generic name of the plants bearing bottle-gourds. 



