294 W. BLAXLAND BENHAM. 
Such is the coarse anatomy of Neodrilus monocystis; 
and though I have done little more than confirm Mr. Beddard, 
I have thought it worth while to illustrate its anatomy. 
The present specimen was found by Mr. Jennings among 
“rotten wood and mould.” 
Plagiocheta punctata, n. gen., n. sp. 
The other worms have a very distinctive shape and colouring, 
and have numerous chete arranged in a nearly complete 
circle! The generic name’ refers to the fact that the chetz 
are always seen crossing the body, whether this is looked at 
above, below, or laterally. Ata first glance, indeed, one might 
mistake them for species of Pericheta (or Megascolex) ; 
but the possession of two pairs of tubular prostates, amongst 
other anatomical characters, removes them from that genus. 
Of this worm there were two complete and mature (?) 
specimens, and two halves of a third, but immature, worm. 
The size and shape of the worm are rather characteristic 
(fig. 14) ; it is 1:6 inches long by 0°5 inch across its widest 
part, which is posterior to the clitellum, so that it is, 
compared to its length, very broad ; it is composed of eighty- 
nine segments. ; 
As will be seen from the sketch, which is twice the size of a 
- spirit specimen, the anterior and posterior extremities are 
nearly similar, tapering gradually to the mouth and anus re- 
spectively. The clitellum forms, so to speak, a waist; but 
that it is in life narrower than the neighbouring anterior and 
posterior regions is, L think, doubtful. 
The body is depressed, so that the dorso-ventral diameter 
is only about half the lateral breadth (Pl. XVI, fig. 17). A 
groove runs along the dorsal and ventral mid-line, which is 
probably due to shrinkage. 
The general colour reminds one somewhat of Michaelsen’s 
1 This suggested the name Cyclocheta for the genus, but Mr. Hatchett 
Jackson has employed the term for a genus of ciliate Protozoa. 
2 ‘Jahrb. d. Hamburg wissensch. Anstalten,’ vi, 1889. 
