CONTRIBUTIONS TO THE ANATOMY OF EARTHWORMS. 433 
Acanthodrilus Dalei, n. sp. 
This species is a native of the Falkland Islands, and is 
specially remarkable on account of its being, apparently, an 
aquatic species. I owe the specimens to the kindness of 
Mr. Dale, who informed me that they were found in fresh 
water; along with them were a num ber of specimens of another 
species, which I believe to bé identical with A. georgianus. 
These are the only two species of Earthworms except Allurus, 
which are known to live in water as well as in earth; at any 
rate this is the case with A. georgianus and Allurus, which 
are both terrestrial and aquatic in their habit. This species 
can be at once distinguished from A. georgianus by its 
violet red colour; the integument of the former species was 
invariably decolourised by the alcohol, and appeared therefore of 
a whitish-brown tint due to the enclosed viscera. All the 
specimens studied by me were small, the largest not more than 
one and a half inches in length. 
The setz are paired, the two sete of the pair being quite 
close together and not separated by an interval as they are in 
A. georgianus. 
The prostomium, as in A. nove-zealandiz, &c., com- 
pletely divides the buccal segment. 
The clitellum was not developed. 
The atrial andspermathecal pores are precisely asin other 
species, i.e. upon the border-line of segments va—vitt, vitI—1x 
and upon segments xvii and xvitt. Of the internal characters I 
am not able to give a complete account, but there are not any 
great differences from such a species as A. novee-zealandiz. 
The gizzard is large and well developed, thus contrasting 
with A. georgianus; it occupies segments vi and vit, and the 
septum between these two segments is present. 
The nephridia are a single pair to each segment, opening 
in front of the more dorsally placed pair of setz. 
The dorsal vessel is single. 
The spermathece resemble in every particular those of 
A. Rose (see p. 485); the minute diverticula are borne at the 
