EQI2; | J. STEPHENSON: Indian Aquatic Oligochaeta. 235 
anterior part was wriggling; the movements of the posterior part; 
when these occurred, were either irregular wrigglings or regular 
undulating movements. ‘The gills in these specimens showed no 
movements of their own when the tail was at rest. The worms 
manifested a sharp and sudden response to a touch with a 
needle ; they contracted somewhat, and then as a rule remained 
quite motionless for a short time, subsequently resuming their 
movements. 
As to their external characters, the gill region was short; 
in one case well developed gills ceased suddenly a little distance 
in front of the hinder end, and behind this point there were 
only tubercles,—about a dozen in both dorsal and ventral series, 
the two or three most posterior being slightly larger than the 
rest ; this peculiarity was possibly due to previous injury. On hold- 
ing the tube up to the light and looking through it the gills were 
invisible to the naked eye in the living animal on account of their 
transparency ; their length was not greater than the diameter 
of the body. The length of the animals was from 1? to 2 inches 
when extended, and their breadth I mm. or more. One specimen 
exhibited genital organs, as described below. 
Again in November ror I received from the Indian Museum 
a tube of these worms, preserved, which had been taken in 
Madras. in the mud from the Victorta regia tank in the Agrihorti- 
cultural Society’s gardens, in September-October, 1907, by Prof. 
K. Ramunni Menon. The specimens were in a bad state of 
preservation, and consisted of 18 fragments, of sizes from 25 to 
2 mm., mostly small; these had apparently belonged originally to 
two worms, of which neither showed sexual organs. The peculiari- 
ty about these specimens was that they were constricted, in 
transverse section, so as to show a somewhat figure-of-eight ap- 
pearance ; but the dorsal, and still more the ventral, surface was 
flattened, the ventral surface, in the region in front of the gills, 
giving the appearance of a flat sole. 
The occurrence of a sexual specimen among the worms 
received from Calcutta offers the opportunity of adding a few 
remarks on the genital organs. The differences between the 
descriptions given by Beddard and by Michaelsen are very con- 
siderable. As briefly as possible, the chief of these are as follows : — 
Michaelsen finds that the vas deferens enters the proximal expand- 
ed portion of the atrium very obliquely through the wall of 
the latter, nearly but not quite at its rounded extremity ; this 
portion of the atrium is lined by long columnar epithelium, 
surrounded by a voluminous investment of glandul:r cells, and 
encroaches posteriorly, where the vas deferens joins it, on segment 
xii. It merges anteriorly into the middle region of the atrium, 
which is narrower, undergoes several irregular windings, and 
before becoming the distal region of the atrium is joined by the 
paratrium. The distal region of the atrium is again wider, is bent 
at its upper end like a hook, but its main portion passes vertically 
downwards to the male aperture. The paratrium is a long 
