444 FLORENCE BUCHANAN. 



in the filament besides the central cavity, and that there is 

 connective tissue between this and the epidermis which has 

 not been preserved, except for a few nuclei (fig. 7 c. t.). The 

 space would then be extension of coelom, and I believe it to be 

 lined by a definite epithelium, although the nuclei indicating 

 this are few and far between. (One is shown at n. in fig. 7.) 

 The clot inside the cavity is more like a coelomic clot than a 

 blood clot. If this central cavity be coelom, I cannot be certain 

 of there being blood-vessels going to the filaments at all (unless 

 certain small structures, seeming to lie in the wall of the 

 central cavity and marked " bl. {?)" in fig. 7, represent them), 

 and the filaments cannot be termed '' branchiae " in the 

 ordinary sense of the word. The extreme thickness of the 

 cuticle would also seem to indicate that their function is other 

 than respiratory, and the peculiar character of the epidermis 

 helps to show what this function is. Although, owing to the 

 method of preservation, it is scarcely possible to distinguish 

 cell outlines, nuclei of the epidermis cells are here and there 

 visible, and grouped around them and apparently densely 

 loading all the epidermis cells are numerous yellow concre- 

 tions, some of them refringeut, others with a somewhat darker 

 appearance, and often massed three or four together. These 

 resemble so closely the concretions of nephridial cells and of 

 the cells of other renal organs described by Eisig in the Capi- 

 tellidae, and behave in the same way towards chemical reagents 

 in as far as I have been able to test them, that I think there 

 can be little doubt of their excretory significance. Eisig has 

 shown how in the genus Capitella, where the nephridia appear 

 not to open to the exterior at all, the excretory products are 

 stored in the epidermis cells, only to be got rid of when the 

 animal changes its skin, and, as is well known, numerous 

 Arthropods normally store their excretory products. The fila- 

 ments, then, on the parapodia of Eupolyodontes Cornishii 

 would seem to be special organs for storing the excretory pro- 

 ducts, and perhaps also for forming them.^ 



' As far as I am aware nothing is known about nephridia or excretory 

 organs of any sort in the sub-family AcoetidtT. 



