56 W. MILNE ON THE 



with maidenliair and other ferns. The ravine is not long, and 

 meets with another larger one at right angles. Within a few 

 feet of the junction, a large rock crosses the bed of the smaller 

 ravine, and slopes steeply down stream. Over this declivity, 

 which is covered with moss, the water glides swiftly. On this 

 moss-covered slope is the home of Monoceros falcatus, and there 

 it literally swarms. For several years I found it there without 

 fail ; then for two or three years I thought it had disappeared, as 

 I could not find a single specimen in the moss brought to me from 

 the ravine. It then occurred to me that the waterfall had been 

 missed, so on the next opportunity I had the moss taken from the 

 rock, and sure enough the animal was again found in abundance. 

 It seems that it requires swiftly flowing water to thrive, at any 

 rate this rock was the only place where I found it flourishing. 



Family Philodinidae. 



DIDYMODACTYLOS gen. nov. 



Generic Characters. — Bbelloida, having two toes only. 



Didymodactylos carnosus sp. nov. 



PI. 2, figs. 2-2c. 



Specific Characters. — Large and massive; corona one-half 

 wider than collar. Antenna very short ; no eye-spot. Invest- 

 ment of stomach yellowish. Foot very short, of four segments. 

 Spurs short, straight cones rising out of great globular or spherical 

 bases without interspace. Toes, two. Teeth, four or five. Size, 

 l/50th inch. 



This is a handsome animal, so Philodina-looking that I took it 

 for one without suspicion, until I caught sight of the toes, and 

 became aware that it had only two, distinct and well developed, 

 and with no signs of any reduction. They are extruded from 

 a narrow rectangular orifice, and can be seen extending through 

 the sheath (PL 2, fig. 26). In 1886 (2) I pointed out that the 

 number of toes formed a very natural means of generic distinc- 

 tion ; and as that method has been utilised by Bryce in his classifi- 

 cation, it followed that a new genus was rendered necessary for 

 this animal. 



The corona is very wide and attractive, and equal to about one^ 

 fourth of the length of the animal when creeping and fully eX' 



