BY E. J. GODDARD. 



i71 



to the 20th, that is, it extends through annuli 14-27, in its 

 normal retracted condition, and constitutes fully one-third of the 

 body in thickness. It measures about 2 mm. in length, passing 

 into the oesophagus at about the position of the male genital 

 aperture. 



The oesophagus is short, extending through only two annuli, 

 namely 28 and 29. In longitudinal vertical sections it is readily 

 distinguishable from the crop by its much narrower lumen and 

 the irregular folded nature of its epithelium, grading, as it does, 

 from the proboscideal nature to that of the crop, and differing 

 markedly from the proboscis by the absence of the strong circular 

 muscular fibres so abundantly developed in the latter, and, in 

 general, by the more feebly developed musculature. The pro- 

 boscis and oesophagus lie in somites vii.-xii. 



The crop bears six pairs of c^eca, a pair aiising behind each 

 pair of testes, and thus occurring in somites xiv.-xix. The last 

 pair are long and lobed, as in G. heteroclita, thus diff'ering from 

 the simple unlobed cseca of G. stagnalis, G. fusca, and G. para- 

 sitica, to which in other respects it is so closely allied. 



The stomach is provided with four pairs of auricular sacs which 

 are found to lie in somites xix.-xxii., the first pair really arising 

 in somite xx., but extending forwards into xix., and, as in the 

 case of the crop-cseca, representing an originally metameric 

 arrangement. 



Reproductive organs. — There are six pairs of testes in most 

 species of Glossiphonia. They lie in annuli 32, 33, 34; 35, 36, 37; 

 38,39; 41,42; 44,45; 47,48. Three annuli thus intervene 

 between the anterior limit of any one testis and the anterior 

 limit of the next, and all are found to lie intersegmentally in the 

 following somites ^,^ ^^,^^,^^^^ as in species of 



^ XIV. XV.' XVI. XVll. XVlll. IIX. ^ 



Glossiphonia in general. The regularity about this interseg- 

 mental position of the testes enables one to use it as a ready 

 means of checking the somites in sections of the organism. 



The ovaries lie in the usual position, as two unequal sacs, one 

 extending backwards to about annulus 46(somite xviii.), and the 

 other to about annulus 42(somite xvii.). 



