1892.] NEW SPECIES OF EARTHWORMS. 151 



pair to each " segment " and that has disappeared. It seems to me 

 that we can just as readily explain the apparent anomaly of the 

 nephridiopores being in the middle of the space between two septa 

 by a reference to other genera in which the areas of attachment of 

 septa have shifted from their original position, as I have mentioned 

 in M. belli. Rosa notes it in Hormogaster^ and Beddard has re- 

 ferred to a similar partial shift of the septa in Libyodrilus ^. 



With regard to the papillae which exist on the 25th annulus ("seg- 

 ment " of Michaelsen) in K. madagascariensis and on the 26th in 

 K. longus^ the suggested modification of enumeration brings each to 

 somite xvi. Michaelsen refers to them as carrying the apertures of 

 the sperm-ducts ; but as he saw no sperm-duct it is quite as probable 

 that they are independent copulatory structures, similar to those I 

 have described in the two species of Microcliceta. The interpretation 

 which he gave to them, however, is quite natural, and I myself, till I 

 cut sections through them, presumed that they were the indications 

 of the spermducal pores, and we, as I have mentioned, know of no 

 other instance (except certain papillae in Perichceta, sp., whose struc- 

 ture is unknown) of such organs independent of the sperm-ducts. 



According to my view, then, the genus Kynotus is not so aberrant 

 as Michaelsen believes. The genus is a near ally of Microchtsta, if, 

 indeed, it be not identical with it, the link between it and M. rappi 

 (the " type" of the genus) being provided by the new species described 

 in the present paper ; and were it not for the very close agreement 

 between these species and the two earlier known species of Micro- 

 chceta (especially in regard to calciferous gland, " hearts," doubling 

 of dorsal vessel, extent of clitellum, position of nephridiopore), I 

 should have referred them to Michaelsen's genus. 



EXPLANATION OF PLATES VII. & VIII. 



Figures 1 to 4 illustrate the anatomy of Plutellus perrieri. 

 Fig. 1. View of the ventral surface of the anterior end of the worm, showing the 

 arrangement of the chastse (the dorsalmost on each side not being 

 visible), the male pores {S)> the extent of the clitellum. Be, pro- 

 truded buccal cavity. 



2. Diagrammatic view of a portion of the body-wall, extending from the 



mid-ventral line {M. v.) to mid-dorsal line {M.J).). The ch^tse 

 (1,2,3,4) have the true relative spacing; we/j^.o., nephridiopores ; 

 spth.]}., spermathecal pores. 



3. Setnidiagrammatic ^iew of a sagittal section through the first twenty 



segments : parts represented as cut through are drawn from the actual 

 section ; organs lying beyond these cut surfaces are put in from 

 other sections. The dotted lines on the dorsal surface indicate the 

 boundaries of somites — in the actual sections they are not present. The 

 septa are represented black, in order that their course may be the 

 more readily followed. 



Bito., buccal cavity ; cer., brain ; ci.ro., ciliated rosette ; circ, circular 

 muscles of the body-wall; Comm., the peripharyngeal nerve com- 

 missure ; gang'., the subpharyngeal or first ventral ganglion ; gen.d., 

 the " genital duct " ; giz., gizzard ; Ig., longitudinal muscles of the 



^ " Sulla strutt. d. Hormogaster redii," Mem. d. E. Accad. d, Sci. d. Torino, 

 ser. 2, vol. xxxix. 



^ " On the Structure of an Earthworm allied to Nemertodrilus," Q. J. M. So. 

 xxxii. p. 546. 



