65 



Behind the 25th foot the inner gill rapidly increases in size 

 and inchnes inwards over the dorsum, the tips turning forwards 

 when they meet in the middle line. Coincident with the change 

 in the inner gill, the dense row of ventral bristles diminishes in 

 size and strength (the 28th foot terminating the larger anterior 

 series) so that at the 45th foot (Plate V., lig. 29), the ventral 

 division has assumed the shape of a short broad leaf with 

 a few short blunt bristles in front of it- ventrally a short 

 tuft of linelv tapered serrated bristles, and dorsally a longer series 

 having the same structure, Dorsally is the longer lanceolate 

 process, which like the ventral has its convex base external, and 

 the long tuft of tapering serrated bristles. Internally is the 

 vascular and richly ciliated gill, the tip of which is tapered and 

 •devoid of cilia. 



At the 70th bristled foot the change is small, viz., a slight 

 diminution of the ventral lobe which also has lost its external 

 convexity at the base. 



Little alteration occurs towards the tip of the tail except the 

 increase of the dorsal lanceolate lobe which is carried erect, and 

 the slight diminution of the branchiae on the more limited 

 surface, for they are continued to the anal funnel. This region 

 of the bodv is readily reproduced, but its precise condition in 

 the adult as contrasted with the young is still in need of eluci- 

 dation. 



A whitish encapsulated body occurred on the ventral edge of 

 an anterior foot. The capsule was filled with somewhat coarse 

 granules. 



A small Isopod was found on the surface of an example, but 

 its presence may have been accidental. The head had tw(3 

 black eyes, and was followed by 7 segments and the 

 telson. 



This species is at once distinguished from Aricici Luvici-i. by 

 the condition of the dorsum anteriorly, and the absence of the 

 pectinate rows of papilhe in the same region laterally. It is, 

 however, in all respects an Aricia. 



Schmarda's genus Aiifliosfoiiia, which he constituted for the 

 reception of the species from the Cape and one from Jamaica, 

 had little that was definite in it, the characters being as follows : — 

 Tentacles and tentacular cirri absent. Segments differing. A 

 lobate proboscis. Branchiae (cirri) with the exception of the 

 anterior segments, three in number, and so with the bristle-tufts. 

 Capillary and aciculate bristles. Fritz Miiller appears to have 

 included the same type in his genus Thcodiscd — afterwards more 

 fully exemplified by Claparede, whose diagnosis is : — Ariciidie 

 with strap-like branchi.'e ; distichous feet the inferior division 

 bilabiate. Proboscis extensible as a digitate membrane. Head 

 devoid of tentacles. 



