/ 
Earthworm from Ecuador. 239 
first somite, so that the first chetigerous somite is the third. 
All the cheete are ornamented in the manner characteristic 
for the genus, and somewhat similar chete are foundin Uro- 
cheeta, Deodrilus*, and Onychocheta (Diacheta) Windley? fF, 
in Anteus t and Geoscolex §, and in Wcrocheta papillata and 
M. Belli (Benham). 
The ornamentation, which consists of a series of trans- 
versely-arranged crescentic ridges, is not so pronounced as 
would appear to be the case in other species; indeed, when 
the cheta: are mounted in glycerine, the markings ‘might 
easily be overlooked with a low power, but in spirit and 
water they are distinctly visible. There are no specially 
modified “copulatory ” cheete, such as exist in the other 
species, where they are larger and straight, in R. paradoxus 
on somites xvi. to xix. and in 22. Gulielmus on the clitellum, 
or larger and more distinctly marked in R. Zenkated; nor do 
I find any fascicles of cheetzs such as Horst described in. his 
specimens on somites XVil., XVil., and Xix. 
The prostomium appeared from the exterior as a small 
rounded lobe, but on dissection was found to be retracted, as 
Beddard found to be the case in his species: it is some 
two or three times as long as the organ in the majority of 
earthworms. 
The clitellum is very distinctly marked, partly from its 
colour, but chiefly from the thickness of the epidermis and 
the deep, conspicuous, intersegmental grooves; it is, as in 
the other species, “ incomplete, and occupies somites xiv. to 
xxv., the last two somites, however, being less distinctly 
modified on the animal’s left side. The latero-ventral 
boundary of the clitellum is nearer the middle line on somites 
xiv. to xix., and here involve the inner couple of chet; on 
ihe posterior somites xx. to xxv. the edge of the clitellum is 
bordered by a series of glands—the tubercula pubertatis— 
forming asemitranslucent band placed between two couples of 
chete, though nearer to the inner couple. A similar band 
exists in the other species, and in the case of Horst’s and 
Perrier’s species appears to be the only representative of the 
clitellum, the animals not being quite mature. In Jt. Ten- 
kate¢ theseven pairs of tubercala traverse somites xx. to xxvi. ||, 
* Beddard, Quart. Journ. Micr. Sci. xxx1i. p. 467. 
+ Beddard, bid. p. 159. 
t Horst, ‘ Notes from the Leyden Museum,’ vol. xiii. 
§ Beddard, ‘ Annals,’ Feb. 1892. 
|| I may say that Horst appears in some doubt as to his numbers, as 
he places the tubercula on ‘* 20th (21st)-26th (27th)”; again, he men- 
tions an “ oliv e-green ring around the body from the 1: 2th (11th)- 15th 
(16th) segment,’ 
17# 
