MALE. 195 



figured, the great basal articulation or pedicel, almost 

 equals in length, and much exceeds in thickness, the four 

 segments of the ramus ; these segments are furnished on 

 their upper dorsal edges with little brushes of spines, but 

 have not even a trace of the normally larger and far more 

 important anterior spines. In one specimen, the anterior 

 cirrus had a large pedicel, carrying three segments, like 

 those of the posterior pair ; but in another specimen, one 

 of the three segments showed traces of being divided into 

 two, thus making four imperfect segments; whilst on the 

 corresponding side of this same individual there were only 

 two ill-formed segments, with their few spines differently 

 arranged. Again, in a third specimen, the great basal 

 segment of the anterior cirrus on one side, bore, exteriorly 

 to the usual ramus, a single segment furnished with 

 bristles, and evidently representing a second ramus ; thus 

 showing that the great basal segment certainly answers 

 to a pedicel. I may here add, that on the integuments of 

 these cirri, I observed with a high power, the serrated scale- 

 like appearance common in other Cirripecles. Directly 

 between the bases of the sixth cirrus, there is a very 

 minute papillus, which, under the highest power, can be 

 seen to consist of two closely approximate, flattened 

 points ; these, I have no doubt, are the caudal appen- 

 dages in an extremely rudimentary condition, for I traced 

 the vesiculae seminales to this exact spot : close outside 

 these rudimentary points, on a slight swelling, is the 

 anus. It will presently be seen that in the male of the 

 closely allied Ibla qitadrivalvis, the nature of these caudal 

 appendages admits of no doubt, for in this species they 

 consist of more than one segment, are spinose, and close 

 under them towards the mouth, there is a perfectly distinct 

 papillus, representing the usual proboscifonned penis. 



Alimentary Canal. — The oesophagus is very narrow, 

 and of remarkable length ; from the orifice under the 

 mandibles, it first runs back (in this respect not well 

 represented in PI. V, fig. 1,) under the bullate labrum, 

 and then straight down the peduncle, where it terminates 



