STRUCTUKE OP TWO NEW GENERA OF EARTHWORMS. 241 



family as defined by myself.^ This, althougli a small point, is 

 an additional argument in favour of retaining that family 

 within the limits which I have proposed for it. 



The structures in question are visible in the epidermis 

 when the body-wall is examined as a flat preparation in 

 glycerine ; and they may be observed to be scattered irregularly 

 over the segments, thus aflfording an example of another 

 system of organs which have no perceptible relation to the 

 metamerism of the body. In a preparation of this kind the 

 sensory organs appear as longitudinal furrows, longer than 

 broad, arranged after no system that I could discover, save 

 that they were absent upon the intersegmental furrows. In 

 transverse sections of the body-wall (cf. fig. 3) the sensory 

 organs are seen to lie in the epidermis, but not to reach its 

 surface ; they generally cause the membrane which separates 

 the epidermis from the underlying layer of transverse muscles 

 to be bulged out towards the latter. Above each body is a 

 row of short epidermic cells which divide it from the cuticle. 

 The real form of the sensory bodies is better seen in longitu- 

 dinal sections, for they lie for the most part parallel with the 

 long axis of the body of the worm. 



In such a section each sensory body is seen (see fig. 2) 

 to consist of a central cylindrical core faintly stained by 

 borax carmine, in which are embedded a variable number of 

 large oval nuclei. Round the axis are a series of coats like 

 those of an onion, which seem to be composed of an elastic 

 membrane ; in such sections, and in the transverse sections 

 also, these coats appear as highly refracting fibres. In frag- 

 ments of the skin mounted entire and viewed from above, the 

 membranes present the appearance of a series of fine striae 

 surrounding the axis of the body. Between the several mem- 

 branous coats are darkly staining nuclei which are quite 

 distinguishable from those which lie in the axis by their very 

 much smaller size ; the central nuclei are fully twice the size 

 of the peripheral nuclei. 



' In a forthcoming resume of the classiQcation and distribution of Earth- 

 worms to be pubiislied in tiie ' Proceedings of the llojal Physical Society.' 



