146 DR. W. B. BENHAM ON [Feb. 16, 



definite spots, lias taken the place of, or is developed in addition to, 

 this clitellar sucking arrangement. 



It is very generally believed that in Lumbricus herculeus, Savigny 

 (L. terrestris, auct.), a mucous band is developed around the bodies 

 of the two worms during the process of copulation : but, from my 

 own repeated observations of the act in Lumbricus, I can state, as 

 some of the older authors have stated, that such a baud does not 

 exist. There is such a band in Allolobophora foetida and no doubt 

 in other species, but in Lumbricus the two worms are joined 

 together, and that pretty firmly, by the action of the tubercula 

 jmbertntis, and no doubt by a certain amount of sucking-action, 

 exerted by the ventral region, not only of the clitellum, but also of 

 all that part of the body lying between that and the fifteenth somite, 

 which is converted into a groove by the action of a band of muscles 

 passing from one side to the other — the arched muscles \ 



In worms, such as Perichata and Acanthodrilus, &c., where the 

 clitellum is "complete" or nearly so, and where no tubercula 

 pubertatis exist, there is no evidence of any power of converting the 

 ventral surface of the body into an adhesive apparatus : and it is in 

 tliese forms that a (probably) protrusible penis — or muscular duct of 

 the prostate — exists. This organ has either (1) actually replaced the 

 adhesive arrangement such as exists in Lumbricus, in which case the 

 sucking-j.apillse, independent of the sperm-duct in Microchceta and 

 the (probably) similar apparatus around the male pore in Geoscolex, 

 Brachydrilus, Criodrilus, may represent stages in the process ; or 

 (2) the two modes of copulation may have arisen independently. 



The Internal Anatomy. 



In the arrangement of its internal organs M. papillata agrees 

 closely with that of the previous species. 



The nephridia, though smaller, present the characteristic tuft 

 of coiled tubules at the end of a fairly large bladder ; the " fine 

 tube " ^ presents the same peculiar branching and anastomoses that 

 I have described for M. rappi^. 



The dorsal blood-vessel is doubled in the somites v., vi., viL, viii., 

 and ix., and in the last somite is dilated to form a double heart-like 

 organ ; in each case the two vessels unite at each end of the 

 somite to form a single tube perforating the septa ; in M. rappi 

 this doubling occurs in the same somites, but in M. beddardi it is 

 limited to somites vii., viii., and ix. 



Large moniliform " lateral hearts " exist in the present species in 

 somites ix., x., xi., and smaller ones in somites vii. and viii., as in 

 M. rappi. 



With regard to the alimentary tract, the chief features to be noted 

 are (a) the gizzard, which appears to occupy somite vi., and (Jj) the 

 oesophageal diverticula or calciferous glands ; of these there is but 



' Oerfontaine, "Rech. sur le Sj-st. cutane et sur le Syst. inuBCulaire du Lomb. 

 ten-.," Arch, de Biologie, x. 189U, pi. xii. fig. 26, p. 407. 

 - " The Nephridium of Lumbricus" Q. J. M. Sc. xxxii. 

 ^ Q. J. M. Sc. Kxvi. pi. xvi. fig. 21, and pi. xvi. bis fig. 31. 



