THE NEPHRIDIUM OF LUMBRICUS. 317 



funnels in Oligochseta, a character ^hich, with the rapid exten- 

 sion of our knowledge during the last five years, has received 

 considerable attention, owing to the careful researches of 

 Beddard, and, more recently, of Spencer. 



The species, of which I hope to give a more detailed account 

 in a future paper, appears to be a new one, to which I give 

 the above name. It agrees with P. quadrigenaria, Perrier, 

 P. elongata, Perrier, and P. exigua, Fletcher, in possessing 

 only one pair of spermathecae ; but it diflPers from each of these 

 three species in various anatomical features. 



As the funnel of the nephridium, which has the typical plec- 

 tonephric character, differs from that figured by Beddard (6, 

 pi. xxiii, fig. 10) for P. aspergillum, it appears worth while 

 to give a figure of it (see PI. XXIV, fig. 25, a and b). It con- 

 sists of eight or nine marginal cells set in a circle around the 

 terminal aperture of the tubule. All the cells are equal in size, 

 and each is ciliated over the whole of the centrally directed face, 

 the other face being covered by a few ccelomic epithelial cells. 

 There is no " central cell,'' nor any centrifugal gutter cells. 

 In P. aspergillum, however, the marginal cells are arranged 

 in a horseshoe fashion, as in Lumbricus (see Beddard's 

 drawing), but without the marked incurving of that genus, 

 although a few smaller cells figured may represent either the 

 completion of the circle or the '^centripetal cells.'' However 

 that may be, the funnel in this species, having a greater 

 number of cells (some fifteen in number), which vary in 

 size, is at a higher stage of development than that of P. 

 malamaniensis. 



I will add a few remarks and suggestions as to the funnel in 

 various earthworms ; for although there are but scanty mate- 

 rials for generalising, yet I think that, even with the few 

 careful descriptions and figures, we can make out something 

 of the evolution of the nephrostome in Oligochaeta. 



More or less careful figures of the funnel of Pericheeta, 

 Megascolides, Urochseta, Microchseta, Urobenus, 

 Criodrilus, AUolobophora, and Pontodrilus occur in 

 the literature (see above) ; but the majority of authors have 



