368 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Anatomy of Ocnerodrilus.* — Mr. F. E. Beddard takes the oppor- 
tunity of having discovered a new species of this interesting genus fi oni 
British Guiana, which be calls 0 . Eiseni, to give an account of its 
anatomy. He is led to the conclusion that it is necessary to form for 
it a distinct family (Ocnerodrilidae), which may be defined thus : — Small 
Oligocbaeta with paired setae of lumbricid pattern ; testes two pairs in 
segments x. and xi.; vasa deferentia open on segment xvii. in company with 
an atrium lined by a single layer of cells, and divided into a glandular 
and non-glandular portion. Ovaries paired in segment xiii. ; oviduct 
open on xiv. ; ova moderately large ; septal glands, but no gizzard ; a 
single pair of glandular diverticula of oesophagus in segment ix. ; 
nephridia abortive in some of the genital segments, and, in the posterior 
region of the body, imbedded in a mass of large vesicular peritoneal 
cells. 
The relationship of this to allied forms is represented in the diagram. 
New Genera of Aquatic Oligochaeta.f — Mr. F. E. Beddard gives an 
anatomical description of two new genera of aquatic Oligocbaeta from 
New Zealand, which he calls Phreodrilus (P. subterraneus sp. n.) and 
Pelodrilus (P. violaceus sp. n.). The first of these does not fit in 
perfectly with any one of the known families of the group, and the 
author, therefore, institutes for it a new family — the Phreodrilidae. It 
is characterized by having the setae in four rows ; the dorsal setae being 
long and capilliform, two to each bundle in the anterior and one in the 
posterior segments. The ventral setae are of two kinds — one of each 
being in each row— curved and S-shaped without a notched extremity. 
The testes are in segments x and xi , and form a continuous mass on each 
side, perforating the intermediate septum. The long atrium, somewhat 
like that of the Tubificidae, has no prostate or penis ; the whole of the 
alimentary tract, with the exception of the buccal cavity, is ciliated, as in 
Phreodrilus, the Naidomorpha, and other lower families of the Oligo- 
cbaeta. 
Pelodrilus appears to be one of the PhreoryctidaB, but it is more like 
the Earthworms than is Phreoryctes itself, and it serves to link more 
closely the family in which it is placed with the higher OligochaBta. 
* Trans. Roy. Soc. Edinb., xxxvi. (1891) pp. 563-83 (1 pi.), 
t Tom. cit., pp. 273-305 (3 pis.). 
