166 ANTHURID. 
five basal segments of the tail, the smooth surface of 
the middle tail-piece, oval at its extremity, the very 
distinct and oval terminal division of the inner plate of 
the side appendage of the tail, and the smaller and 
narrower size of the outer division. The hand of the 
fore pair of legs also wants the notch along its under 
edge. It is ofa pale bone colour, covered with minute 
black dots. The mouth is enclosed between horny 
plates (+) and furnished with a pair of straight, elon- 
gate-conic mandibles, pointed at the tip, having a large, 
three-jointed, palpiform appendage fixed at its base on 
the inner edge. The maxillze consist of a pair of long, 
very slender, slightly curved, lancet-like pieces, retro- 
serrated at the apex, and the mouth is closed beneath 
by a broad pair of foot-jaws, which are terminated by 
two large, flat joints, the apical one being strongly 
ciliated. 
In all these particulars it perfectly agrees with other 
specimens preserved in spirits in the same collection, 
with a label inscribed “‘ Anthura gracilis,” in the hand- 
writing of Signor Costa, of Naples, with whom Mr. 
Hope was long in friendly communication upon the 
marine animals of the Mediterranean. On referring to 
Mr. Hope’s catalogue of the Mediterranean Crustacea, 
we find only one species of Anthura indicated with the 
name of A. gracilis, which, from a copy marked by S. 
Costa, we find to be in his collection; and we have, 
therefore, no doubt that the species was communicated 
by him to Mr. Hope. We therefore at first hesitated 
to consider the species as a real native of this country 
(fearing some confusion might have occurred as to the 
labels of the South Western Coast specimens), and, in 
honour to Signor Costa, we proposed for the species the 
name of Paranthura Costana. Whilst, however, this 
