116 Mr. F. E. Beddarcl on the 



])avc a ]aio;c tcvmiual sac; Lut tliis lies along the transverse 

 axes of the body in close contact witli the septa and is 

 fiivnislicd with a ca?cum -which lies on the distal side of the 

 external pore. 



Perrier has indeed remarked that the posterior nephridia of 

 Anieus gigas are less in calibre tlian the anterior and are 

 attached by a membrane not rein-csented in the anterior series ; 

 but he says nothing of the caecum (supposing it to exist in 

 that species). 



It is frequently the case in this family of earthworms 

 (Geoscolccidffi) that the anterior nejjhridia differ in structure 

 from the posterior. In liJnnodrilus Guliehni * precisely the 

 same differences exist as in the present species. 



The present species of Anteus, like the other species of the 

 genus and like so many other earthworms, has several 

 specially thickened septa lying in the anterior region of the 

 body. In Avtens heterosticlion there are four of these imme- 

 diately following the gizzard and separating segments vi./vii., 

 vii./viii., viii./ix., ix./x. ; behind these is another, thinner, 

 septum which largely covers the septum in front, just as these 

 cover each other successively in the way that Perrier has 

 described. 



Species of Auteus. 



Is the above species really distinct from Aniens gigcis 

 described by Perrier, and more recently by Horst ? I am 

 convinced that it is distinct, and, moreover, I believe that 

 Ilorst's species is not the same as either Perrier's or the one 

 that I have just described. 



The points of difference between Anteus heterostichon and 

 Anteus gigas are of course to be found mainly in the diver- 

 gence of the setae posteriorly and in the commencement of the 

 posterior set of nephridia in the thirteenth instead of the 

 twentieth segment in the latter species. There can be no 

 confusion as to these points, as Perrier's description is perfectly 

 clear. AVith regard to the setai he says (p. 52), " Les soies 

 sont disposecs, comme chez le Lombric ordinaire, en quatre 

 rangees de paires, deux rangees sont franchement ventrales, 

 deux laterales. Ces rangees sont constamment parall^les 

 d'une extremite a I'autre du corps, et les soies de chaque 

 paire sont toujours trbs-rapprochees I'une de I'autre." 



Dr. Horst considers that the species which he investigated 

 is Anteus gigas. But in that form, as in Anteus heterostichon 



* Beddard, he. cit., woodcuts figs. 5 aiid 6. 



