1886.] MR. F. E. BEDDARD ON A LARGE EARTHWORM. 169 
drilus’. This genus is already known to inhabit New Caledonia ; 
M. Perrier bas des¢ribed two distinct species from that region. The 
species which forms the subject of the present communication may 
be identical with one or other of these. The descriptions given by 
M. Perrier of Acanthodrilus obtusus and A. angulatus are necessarily 
insufficient, owing to the poor condition and immaturity of the 
specimens at his disposal ; but certain facts, such as the position of 
the generative apertures and of the clitellum, could hardly be 
mistaken even in specimens greatly injured through bad preservation ; 
in these points the present species differs from both of those de- 
scribed by Perrier, as will be apparent from the following notes on 
its structure. 
External Characters.—I have sketched (Plate XIX. fig. 1) the 
anterior segments of the body from the dorsal aspect to indicate the 
main external features which are visible upon that surface. The 
buccal lobe divides the first segment *, as also in A. dissimilis and 
A, nove zelundie, two species recently described by myself *. Ofa 
fourth species of the genus, viz. 4. verticillatus, M. Perrier writes * :— 
** La lobe céphalique n’entame pas le premier anneau et parait au 
contraire s’elargir asa base de maniére aressembler a la partiesupérieure 
d’un tréfle ; mais cette apparence tient peut-€tre a un état particulier 
de conservation.” J mention these facts because the genus Lumbricus 
has been split up into other genera mainly on this account. It does 
not appear to me advisable, while there = so many internal structural 
differences, to make use of so small an external character for 
classificatory purposes ; but in the case of the genus Acanthodrilus 
this mark of difference between species appears to be correlated with 
other differences of structure, inasmuch as M. Perrier hesitates to 
include A. verticillatus in the same genus with A. odbtusus; the 
male generative pores in the former species are upon the 17th 
and 18th segments and are not separated by an intercalated segment 
as in the Jatter and all the other species of the genus at present 
known. On either’side of the buccal lobe, and consequently between 
the first and second segments of the body, is a single pore; these 
may perhaps correspond to the single median dorsal pore which is 
the only orifice of the kind found in the Oligocheta limicole. 
The celitellum was fully developed in several specimens, and 
extended from the 13th to the 17th segments inclusive, with the 
exception of a portion of the 13th segment; the glandular tissue 
composing the clitellum was only visible on the posterior half of that 
segment ; the clitellum extends occasionally for a short distance on 
to the 18th segment. The anterior region of the clitellum down to 
the 15th segment completely encircles the body ; the 17th and 18th 
segments, on the contrary, have a very considerable median area upon 
which there is no glandular development ; the lateral margins of this 
? Perrier, “Recherches pour servir alhistoire des Lombriciens terrestres,” 
Nouy. Arch. d. Muséum, t. viii. (1872) p. 85. 
* I have reckoned the first seta-bearing segment as the second segment of the 
body, in common with the majority of naturalists who have studied this group. 
* P.Z.S. 1885, p. 813. * Loe. cit. p. 93. 
Proc. Zoo. Soc.—1886, No. XII. 12 
