322 POLLICIPES MITELLA. 



transverse ridge, running from the base of the first cirrus 

 to near the adductor scutorum muscle : these ridges seem 

 formed merely to allow of the larger development of the 

 testes. 



Mouth. — Labrum highly bullate; crest without any 

 teeth, but with a few minute hairs. The inner fold of the 

 labrum forming the supra-cesophageal cavity, is thickened, 

 and shows a trace of a central line of junction, as in Sessile 

 Cirripedes. 



Palpi (PL X, fig. 7), small ; of a singular club-like 

 shape, owing to the convexity of the outer margin ; exterior 

 spines long, all doubly serrated. 



Mandibles (PL X, fig. 1), with five teeth, of which the 

 second is very small ; inferior angle coarsely pectinated. 



Maxilla (fig. 14), with a deep narrow notch (bearing 

 some fine spines) beneath the two upper great spines, 

 which stand on a prominence; edge straight, bearing 

 fourteen or fifteen pairs of spines : on the inferior angle 

 there is an obscure tuft of shorter and finer spines : apo- 

 deme long, sinuous, and slender. 



Outer Maxillce (fig. 17), with the inner margin divided 

 by a deep notch into two lobes, of which the upper one 

 is rather short ; both are clothed with a compact row of 

 short bristles ; exterior margin with longer bristles. 



Olfactory Orifices, large and prominent to an unusual 

 degree. 



Cirri, moderately long and curled j the four posterior 

 pair are alike j each segment has its anterior face some- 

 what protuberant, and bears six pairs of long spines, with 

 a rather large, narrow tuft of intermediate spines, some 

 of which are finely and doubly serrated. The dorsal tufts 

 consist of short, thick spines, with some fine longer ones. 

 The first cirrus is seated near the second; its rami are 

 slightly unequal in length; lower segments paved with 

 bristles ; one ramus is thicker than the other, and some 

 of its segments have coarsely pectinated spines. Second 

 cirrus has the five basal segments of its anterior ramus 

 highly protuberant, and paved with bristles, of which 



