522 SUPPLEMENT 



only by the absence of mandibles and palpi, but still further 

 by the shorter proportions of the body and the feet. The feet 

 appear to have an articulation less than in the other pycno- 

 gonides. The last but one appears to form, in the pycnogona, 

 only a small inferior knot, and joining the last articulation of 

 the tarsus with the preceding. 



But a single species appears as yet to be known, the 

 P. halanarum, figured by Briinniche, Miiller, and some other 

 naturalists. It is found under the stones on the shores of the 

 European ocean ; it is rare on the coasts of England and 

 France. 



The genus Phoxichilus M. Latreille at first thought to 

 differ from the preceding, in having mandibles, and from the 

 succeeding {Nymphon), by these organs being terminated by a 

 single digit, and by the want of palpi as in the former genus. 

 But having subsequently examined, with more attention, the 

 mandibles of the species in which he had established this new 

 generic section, he observed that they terminated in a didac- 

 tylous forceps, in the same manner as those of the nymplwns, 

 and that the inferior digit, covered by the ordure which at first 

 had prevented him from perceiving it, was only smaller than 

 the superior one, or that which is mobile. But the Phoxichili 

 are, nevertheless, strongly distinguished from the nymphons, 

 by the absence of palpi. They are also removed from them 

 in other points of view — 1. The tube, or siphon, forming the 

 sucker, and the aperture of which represents a trefoil, as is 

 the case with that of the same part in other animals of this 

 family, is bellied in the middle, a little narrowed afterwards, 

 and is terminated by a rounded expansion furnished with 

 hairs. Each of its sides, and the middle of its back, presents 

 two impressed longitudinal lines, and which, uniting by their 

 extremities, describe a sort of ellipsis. In considering these 

 lines as sutures of united pieces, this tube would be composed 

 of six valvules, or laminae, cemented together, and which 



