new Species of Harthworms. 55 
Traces of clitellum begin on segment 13, but become 
strongly marked on segments 14-33, 36 (=23 somites). 
The clitellar somites 25-324 bear latero-ventral wing-like 
expansions with either a straight or greatly-folded margin. 
The limits of the clitellum at either end are indistinct. The 
Fig. 2. 
Pees. 
#5 Ge tt ee 
< PEO e is g 
Vertical longitudinal section of pharynx and gizzard of G. fluviatilis. 
The section shows the immense dorsal thickening of the pharyngeal 
wall, the ventral thrown into folds so as to give rise to pouch-like 
sacs. 
Lettering to figs. 2-4. 
amp.c. = ampulliform clitellar cells; 6.7. = blood-vessel ; Coel.m. = 
coelomic muscles with clumps of cells on them; ¢.f.=connective tissue ; 
d.v.=dorsal vessel; g.c.=glandular cells ; Giz.=gizzard ; m.=muscular 
system of body-wall; nep.=nephridia ; nep.c.=nephridial cells, showing 
the characteristic form and position of nucleus; ».c.=nerve-cord ; 2.v.= 
subneural vessel; nip.=teat of puberty-tubercle ; 0b.m.=oblique muscle- 
fibres; p.g.=pharyngeal gland; p.p.=pharyngeal pouch; p.s.=peri- 
toneal sheath ; r=rim of puberty-tubercle ; rvg.m.=circular muscles of 
the rim; s=skin; s.¢7.=subintestinal vessel; ¢=typhlosole; ¢.v.= 
typhlosolar vessel; v.=valve-like fold of pharynx; w.t.=wide tube 
free in fig. 4 B and clogged by degenerate nephridial cells in fig. 4 C; 
n.t.=narrow tube free in fig. 4 Band clogged by degenerate nephridial 
cells in fig. 4 C. 
uberty-tubercles occur in three rows in front of the clitellar 
fold, and their number and relation to somites are irregular, 
The mid-ventral row commences on segments 13, 16, extend- 
ing up to segments 23, 24. The number of lateral papilla 
