Earthworm from Ecuador. 243 
which presents this peculiarity, that its line of origin takes a 
spiral course round the wall of the gut; so that we have, in 
place of the straight valve commonly found in earthworms, a 
spiral valve. 
The vascular system presents the characteristic ‘ intestinal 
hearts”? which Perrier was the first to describe, and which 
are now known in other genera than Rhinodrilus; there are 
two pairs only of these ‘commissural vessels in the present 
species, greatly dilated and communicating not with the 
dorsal, but with the * supra- intestinal ” vessel, as Mr. Bed- 
dard has figured for his species; they belong to somites xi. and 
lls, though they appear to lie in somites xiii, and xiv., the 
first passing between the second and third intestinal diver- 
ticula and the second heart between the third and fourth of 
these. 
Immediately in front of Gliese “intestinal hearts” (fig. 3, 
th.) are three pairs of very much smaller “ lateral hearts” 
(.4.) arising from the dorsal vessel; these three lie close 
behind one another between the gizzard and the first diver- 
ticulum. It is a matter of some uncertainty whether these 
lie in somites vill.,ix.,x., or in vil., viil., ix. ‘The dorsal vessel 
(d.v.) isampullated in somite xv. and ineach pute posteriorly, 
where it lies above the sacculated intestine; but anteriorly 
to this, in the region of the “ intestinal hearts” and intestinal 
diverticula, it is practically cylindrical, though it gradually 
diminishes in size, and where the “lateral hearts” leave it 
it has become quite narrow. ‘The dorsal vessel appears to 
terminate behind the gizzard, for 1 could see no median vessel 
beyond this point; Mr. Beddard states (loc. c7t. p. 158) that 
anteriorly to the gizzard the ‘ dorsal vessel runs some way 
above the surface of the cesophagus;” so that it is possible 
that I had removed it in this region, though it seemed to end 
quite definitely behind the gizzard. 
In £. Gulielmus there are three patrs of “ intestinal hearts” 
in somites x., xi., xil., the hindermost pair of which is 
smaller and not dilated ; in front of these there are two pairs 
of narrow ‘ lateral hearts.” 
In R. Lenkated there are also two pairs of lateral hearts, 
which, according to Horst, lie in somites xu. and Xill., and 
behind these are two pairs of “ intestinal hearts,” passing 
between the first and second and between the second and 
third intestinal diverticula. 
With regard to &. paradoxus, the ‘ intestinal hearts ’’ are 
stated to lie in somites xx., xxi., and xxil., though whether 
this apparent position is due to displacement or not can 
only be settled by a renewed examination of the species; it 
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