314 Transactions of the Royal Microscoincal Society. 
The species, while thoroughly preserving all the above-named 
characters of the genus, which are very marked, is, as far as those 
characteristics will allow, a complete contrast to that last described, 
its red or orange colour, lighter build, and longer legs, evidently 
adapted for speed and activity, making it a remarkably different- 
looking creature. 
The median stripe in this species is very conspicuous, and ex- 
tends from the widened oesophagus to near the anus, and is fonned 
by the alimentary canal showing through the skin ; the normal 
shape of the stripe is that of an hour-glass, and the colour is 
opaque white ; the shape of the marking, however, varies consider- 
ably, both in different individuals, and in the same individual from 
time to time, according to the position of the food in the canal, and 
the quantity contained. The body on each side of the median 
stripe is red or orange, the palpi, legs, and oesophagus clear light 
yellow or yellowish white. 
The shape of the body, as in all the Cheyleti, is diamond or 
coffin shaped, with the anterior part of the diamond shorter than 
the posterior, and the front and anal angles rounded off, the points of 
the lateral angles being formed as in the last species ; but the body 
in Venustissinms is longer in shape, being nearly twice as long as 
it is broad, without the rostrum, and much flatter, the thickness not 
being above a sixth of the width at the widest part. The diamond 
shape is not so conspicuous as in the last species ; the body is 
marked by five slight constrictions, which produce a somewhat 
scalloped outline ; the constriction between the cephalothorax, 
wliich occupies over two-thirds of the whole bulk, and the abdomen, 
is only slightly marked on the upper side or at the edges, but on 
the under surface it is marked by a very deep depression, widest on 
the ventral surface, and narrowing inwards ; the raised median 
portion of the under surface of the cephalothorax slopes suddenly 
down from nearly opposite the insertion of the fourth pair of legs to 
the bottom of this depression, forming a blunt oblique triangle. 
The anus is placed in the centre of a strong horseshoe-shaped ridge, 
with the points drawn out laterally, which is marked with 
numerous folds, and is probably contractile. The skin of the legs, 
palpi, and under side of the body is very finely striated ; the stria- 
tion is, however, not nearly so strong as in the last species, and on 
the body the colour renders it difficult to see. 
The anterior pair of legs are far the longest, and very thin and 
fine; these legs constitute the most marked characteristic of the 
species, being strikingly different from the comparatively short firm 
legs of the other Cheyleti, particularly the last species. The coxa is 
short, stouter than the other joints, and is somewhat angled on the 
posterior side. The second joint (or trochanter) is long and 
straight ; it is decidedly striated. The third joint (the femur) is not 
