ACANTHONOTUS OWENII. 
233 
meats of the tail likewise possess a lateral ridge, and the 
posterior margins are denticulated ; the fourth segment 
of the tail is marked, by a deep sinus across the dorsal 
surface. The eyes are round and prominent. The 
superior antennae are stouter at the base than the 
inferior, and are also a little longer. The coxae are 
deep, narrow, and terminate in a point, those of the 
fourth pair of legs being the largest, sickle-shaped, and 
armed with a strong curved spine on the hind margin. 
The first two pairs of legs are very similar ; the wrists 
are a little longer than the hands ; the hands have no 
clearly -defined palm ; and the fingers are very short. 
The rest of the legs are very nearly of the same length ; 
the thighs of the three posterior gradually increase in 
width : they have the anterior portion thick, whilst the 
posterior is suddenly reduced to a thin scale, so that 
the legs, when folded up, lie compactly together in a 
groove. The three posterior pairs of caudal appendages 
are subequal, the branches being of uniform length, 
styliform, and free from hairs. The tail-piece is deeply 
cleft.* 
This animal, according to specimens received from the 
Rev. A. M. Norman and Mr. Jeffreys, is of a fawn 
colour striped with red, the red bands corresponding 
with the posterior margins of the segments and joints 
of the animal. In this it appears to differ from an 
American form, A. serratus, Fabricius, as described by 
Stimpson, where the anterior half of each segment is 
pink, and the posterior white. 
* The figure representing this animal was drawn from a specimen in the 
British Museum, while the description is taken from a specimen captured in 
the Moray Frith. They disagree in some unimportant points ; the telson being 
less cleft in the figure than in the description, and the hands are more dis- 
tinctly subchelate in the former than the latter. 
