ACANTHONOTUS OWENII. 233 



ments 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 coxaa 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. 



