62 MR. F. E. BEDDARD ON [Feb. 4, 



looking bodies in most of the posterior segments of the body ; these 

 are attached, close to the middle line on either side of the dorsal 

 vessel, to the posterior side of the septa. They were perfectly 

 recognizable both in transverse and longitudinal sections, tliough 

 naturally their relations to the septum were better shown by the 

 latter, their position with reference to the dorsal vascular trunk by 

 the former series of sections. 



Structurally tliese small white bodies consist of a mass of cells 

 continuous with the peritoneal epithelium and probably formed by 

 a local proliferation of its cells ; in the interior of each were a few 

 muscular fibres ; there was no trace whatever of a central cavity, 

 which occurs in the corresponding bodies of the allied genus 

 Acanthodrilus. These " septal glands " were in Perickceta indica 

 sohd throughout. 



As to Acanthodrilus the observations recorded in this paper were 

 made upon some examples of Acanthodrilus georgianus (Michnelsen, 

 26), which were collected for me in the Falkland Islands bv Dr, 

 Dale, at the request of Mr. Coleman, Secretary to the Falkland islands 

 Company. 



This worm differs from all other species of the genus, which I 

 have examined, in possessing a series of sac-like organs connected 

 with the septa. These have the appearance of white solid bodies 

 attached to the septum close to the nephridium — a pair to each 

 segment ; they commence at about the 20th segment and continue 

 to the end of the body ; the first three or four pairs are commonly 

 larger than the rest. These organs are not really solid bodies, but 

 sac-like outgrowths of the septa depending freely into the interior 

 of the segments ; they are, in fact, exactly similar to the sperm- 

 sacs and egg-sacs of the same and other Earthworms in their early 

 stages of development ; and their absence in the anterior segments 

 of the body, where the sperm-sacs and egg-sacs are found, may 

 possibly be due to their homology with those structures. 



Each sac has a somewhat racemose appearance owing to the 

 irregular bulging of its walls ; the walls are muscular with a thick 

 coating of peritoneal cells, which are larger and more numerous than 

 those on the adjoining surface of the septum ; the interior of the sac 

 has a delicate lining of peritoneum and communicates with the 

 segment in front by a pore. 



The only structures with which I can compare these septal sacs are 

 the oval aggregations of peritoneal cells described by Ciaparede (26) 

 in tiie common Earthworm. Ciaparede figures and describes these 

 bodies as consisting of a mass of peritoneal cells enclosing a few 

 muscular fibres ; the presence of muscles suggests that the bodies 

 may really be sacs, and not solid proliferations of the peritoneum. 

 Vejdovsky (29) has recorded the presence of similar sacs in Rhyn- 

 chelmis and in Tubifex ; but inasmuch as in Tubifex they were only 

 found in a few cases and in the posterior younger segments, Vejdovsky 

 regards them as connected with the growth of the septa. 



In Acanthodrilus georgianus, as already mentioned, they com- 

 mence iu the anterior region of the body ; and as they were found 



