152 ON NEW SPKCIES OF EARTHWORMS. [Feb. 16, 



body-wall ; Ig'., their distribution to the wall of the buccal cavity ; 

 ne.o., the aperture of the first nepliridium ; ncph'., the first nephri- 

 dium ; ov., ovary ; ov.f., oviducal funnel ; ov.p., oviducal pore ; 

 (es., oesophagus; Thar., pharynx ; fro., prostomium ; frost., prostate ; 

 sal.g., salivary glands ; q).d., sperm-duct ; sf-f-, male pore ; sp.sae, 

 sperm-sac; spth., spermatheca; spth.p., spermathecal pore; T., 

 testis ; vis.n., visceral nerve, from brain to vpall of buccal cavitj' and 

 pharynx ; x, ciliated cells on roof of pharynx. 

 Fig. 4. Transverse section through Plutellus. 1, 2, 3, 4, the positions 

 occupied by the four chffitse on each side ; ep., epidermis, represented 

 as a black Hue; c«r., circular muscles of body-wall; Ig., longitudinal 

 muscles, which form a thinner layer dorsally than ventrally ; B.v., 

 dorsal vessel lying partially surrounded by a " perihsemal cavity " 

 ijp.h.sp.); N.C!., nerve-cord; «'., ventral nerve; «".,ventro-lateral nerve; 

 neph., portions of the loops of a nephridium ; neph.d., nephridial duct, 

 opening at nc.o.; perit.gl., a " peritoneal gland"; sept., septum ; v.v., 

 ventral vessel. 

 6. Ventral surface of MicrochcBta papillata (nat. size), c.p., c.p'., the 

 copulatory papillfs (suckers) on somites x. and xxiii. ; m., mouth ; 

 Pro., prostomium ; t.p.. ridge at each side of clitellar region, probably 

 representing tubercula pubertatis. The roman numerals indicate 

 the somites, some of which are biannulated (a, b). 



6. Side view of M. belli, in oMer to show the deeply marked annulation of 



the somites, a, b, c, the three annuli into which the surface of the 

 somite is divided. The roman numei'als indicate the somites. Buc, 

 the protruded buccal cavity; ne.o., nephridiopore ; l.ch., the outer 

 couple of chaetas ; v.ch., the inner couple of chatte. 



7. The copulatory papilla of somite x. of M. papillata. Pap., the papilla ; 



pap'., the small papilla in the apical cup, showing the pore of the 

 internal organ as a small dot ; V.ch., the ventral chsetse of somite xi. ; 

 v.mid., the ventral midline. 



8. Side view of anterior end of M. beddardi, in order to show the fusion of 



somites i. and ii., referred to in the text, ^rosif., prostomium ; neo'., 

 first nephridiopore. 



9. The " sucker " or internal organ, corresponding to the external papilla 



of somite xxiii. of M. papillata. s.s'., the septa of the segment; 

 m., the muscle of the chsetophore. 



10. A somewhat diagrammatic view of a transverse section of the " sucking- 



organ " (combined from a series of sections). 



Ch., the chsetffi surrounded by the apparatus ; circ, circular muscles 

 of the body-wall, continued over the " sucker"; cl., clitellum ; co.ep., 

 coelomic epithelium covering the organ ; ep., the epithelium lining the 

 " sucker " ; gl. the gland-cells of the organ ; Ig., longitudinal muscles of 

 the body-wall ; m.ch., the muscles of the chaetophore ; miis., the muscles 

 surrounding the " sucker " ; pap., the external papilla ; pap'., the smaller 

 papilla contained in the apical cup of the larger ; pore, the pore of the 

 apparatus. 



11. A portion of the wall of the sucker of 31. papillata ; only a small portion 



is filled in in detail, co.ep., the coelomic epithelium, dipping down 

 between the groups of gland-cells (gl.) ; b.v.. blood-vessels ; ep., epithe 

 Hum of the organ ; mus., muscles in various directions in the wall ; ner., 

 nerves cut across. 



12. The tip of an ordinary chceta of ilf. belli. 



13. The sperm -sacs of M. papillata. A, B, the chief sacs; C, B, the 



smaller posterior lobes of these. A, B have been opened on the right 

 side, showing the contained ciliated rosettes (c.r.) and testes {t.) : cal., 

 caleiferous gland ; gt~., gizzard ; sep., the strong septa. 



14. A transverse section of the tuberculum pubertatis oi' M. belli (only a 



portion is filled in with detail), ej}., epidermis of clitellum ; circ, cir- 

 cular muscles of the body-wall, between the fibres of which the gland- 

 cells of the tuberculum pass inwards ; Ig., longitudinal muscles; b.v., 

 blood-vessels. 



