| OCR Text |
Show 388 MR. F. E. BEDDARD ON TWO [Apr. 17, Nannodrilus, nov. gen. D E F . Small worms with paired setce. Nephridia paired. Calciferous gland in ix. Spermiducal glands two pairs lined by a single layer of glandular cells, opening on to exterior in xvii., xviii. ; the anterior pair open in a bursa copulatrix with, but independently of, sperm-ducts. Spermathecce without diverticula.-Hab. West Africa. This new genus evidently belongs to that group of small-sized Cryptodrilidae which includes the genera Ocnerodrilus, Gordiodrilus, and Pygmceodrilus. They all agree in the fact that the spermiducal glands are lined by a single layer only of glandular cells, a character not found anywhere else except in the Acanthodrilid genus Kerria. The present genus comes nearest to Gordiodrilus; but it should be, I think, regarded as the type of a new genus on account of the bursa copulatrix. In other respects it agrees fairly closely with Gordiodrilus. Nannodrilus africanus, n. sp. D E F . Length an inch to two inches. Clitellum xiii.-xvii. Two rudimentary gizzards in vii., viii. Nephridia begin in v. Spermathecce two pcdrs in viii., ix. As the present is the only species of the genus, the above definition of the species is of course only very tentatively put forward. The clitellum occupies the segments stated in the definition; it extends right round the body and is conspicuous in mature specimens. Such specimens are also always obvious ou account of the protruded penes. These are as long as the diameter of the body. Their structure will be more conveniently deferred until the description of that of the efferent apparatus in general. The intersegmental septa in the anterior region of the body are much prolonged backwards and lie within each other like a series of cups ; those separating segments v./ix. are particularly thickened. The oesophagus runs in a perfectly straight uniform way without dilatations from the pharynx to segment ix ; in segments vii. and viii. it is furnished with rudimentary gizzards, whose calibre is not greater than that of the oesophagus. On a dissection these gizzards would be hardly recognizable ; the increased thickness of their muscular walls entitles this section of the oesophagus to be termed gizzard, but the epithelium has no trace of the thick chitinous lining so constantly associated with the gizzard. In tbe ninth segment is the calciferous gland, which appears to be an unpaired structure. It is constricted in the middle, dividing it into an anterior and a posterior section. The minute anatomy appears to be most like that of Gordiodrilus. The mass of the gland has a granular structure and contains numerous nuclei; but in spite of the undoubted nuclei no cell-boundaries could be detected. The tissue is in fact quite like that which |
