OCR Text |
Show 1903.] NEW SPECIES OF EARTHWORMS. 215 The spermathecal pores are paired, while the male pore is single and median (text-fig. 36, p. 214). The two former pores are upon the boundary line of segments xii./xiii.; each is somewhat eye-shaped in contour and corresponds exactly in position to the outermost of the ventral couple of setae. The single and median male pore lies on the boundary line of segments xvii./xviii. It is very large and conspicuous, with radially folded margins, indicating, perhaps, the possibility of the extrusion of the bursa propulsoria. The internal organs, unfortunately, were much softened, and therefore the female reproductive apparatus was rather difficult to decipher. The nature and relations of the other organs of the body were not so difficult to ascertain. As in many, if not in all, Eudrilidae, the last pair of hearts occurs in segment xi. In front of these were four distinct pairs. The dorsal vessel is single throughout. I have not been able to study the alimentary system in detail, but I have ascertained that the present species is a member of the section Eudrilacea by virtue of the existence of an unpaired ventral median alimentary gland in segment x., which showed on a microscopical examination the usual laminate structure of these glands, not at all to be confounded, even in a badly preserved specimen like the present, with the totally different though corresponding organs in the other subfamily of the Eudrilidae. There are also a pair of these glands in segment xiii., of an oval form, which contain abundant crystals, such as are met with in other genera. Text-fig. 37. Termination of the male efferent apparatus of Bettonia lagariensis. B.p., Bursa propulsoria; Sp.gl., spermiducal glands. The only conspicuous parts of the male generative system are |