218 WILLIAM BLAXLAND BENHAM. 
The clitellum occupies somites xxvii to xxxix, and the 
whole worm has 106 somites. This specimen came from Buenos 
Ayres and elsewhere, and the genus has since been studied by 
d’Udekem, Grube (18), and lastly by Kinberg (19), who, in his 
description of two species, says nothing about the charac- 
teristic ninth seta, whilst no author has given a proper 
anatomical description of any species. 
In 1844 Templeton (20) described a form resembling the 
wide-spread genus Pericheta, but differing from it in the pre- 
sence of an interruption in the dorsal mid-line in the ring of 
sete. He called the worm Megascolex coeruleus; he 
obtained it from Ceylon; its length was from 20 to 40 inches 
by 1 to 1} inch broad ; it contained 270 somites with a ring of 
100 setze on each. This must I think be referred to the genus 
Pericheta. 
In 1845 Hoffmeister (22) described and figured several 
species of Lumbricus (see below), as well as the following 
forms which are European. 
Phreoryctes, which is now placed amongst the Limicole. 
Criodrilus has four rows of paired setx, and is 8 to 12 
inches long, and consists of 300 somites. The male pore is on 
somite XIV. 
Helodrilus is 2 to 5 inches long, contains 160 somites, 
with setz arranged as in the preceding. The male pore is on 
somite xv. 
Neither of the latter has a clitellum. 
In 1848 Rapp (21) described a worm under the name 
Lumbricus microchetus, which is probably the same as 
Beddard’s Microcheta (33) from the Cape. 
In 1851 Grube (23) described a peculiar form which he 
called Lumbricus multispinus; its chief characteristic 
is the possession of four bundles of 5 sete in each somite; 
there was no trace of clitellum. The male pores are in 
somite x1I, in a line with the most ventral group of setz, 
and each carries a papilla. Its habitat is not mentioned, 
nor is the internal anatomy. Leon Vaillant (24) has 
founded a new genus for it, Echinodrilus. Judging from 
