.14 Mr. MoxTacv's Description of several new or rare Animals, 
On V. minutus was another species of Acarus, with only six 
legs of moderate length, and a reddish ovate body.. Whether 
these are new, and each peculiar to the respective bats from 
which they were taken, is not at present to be determined, and 
the remark is only intended for the future observation of others. 
MONOCULUS. 
MoNocUuLUs ROSTRATUS. 
Tan. II. Fig. 5. 
Body ovate, crustaceous, of a pale yellow colour, with a darker 
longitudinal line along each side: antennz four, the superior 
pair bifid near the base, one branch moderately long, the other 
very short ; the lower pair simple, and nearly as long as the body, 
the three first joints large ; all these are hirsute, and incline down- 
wards: eyes two, large, pedunculate, and reticulated, appearing 
in a strong light crimson; these are covered by a pointed beak 
or shield a little incurvated, convex above, and concave beneath : 
natatorial legs three pairs, these are slightly bifid and very hir- 
sute; between these and the front are several fasciculi of bristles: 
tail longer than the body, consisting of five joints elevated at their 
junction, the middle one furnished with two small appendages 
beneath: to the end of the tail are attached two subulate caudal 
fins terminated. by a long setaceous appendage, and covered 
with hair. OMS NAA 
Length to the end of the tail three eighths of an inch. 
When in motion, the fasciculi beneath, which appear to be 
abdominal fins, as well as the superior antenn® were observed to 
be in continual motion; the inferior antenne were usually mo- 
tionless, and brought under the bod No e. 
This marine Monoculus is I believe the largest species this 
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