ALCIPPE LAMPAS. 547 



thorax in two planes, and I subsequently cleaned the outer 

 tissues with boiling potash, and then, when as transparent 

 as a sheet of glass, I examined every part, and certainly 

 there is no rectum (which in every case is formed of chitine, 

 and so is not acted on by potash) nor an anal orifice. Singular 

 as this fact is, it is not so improbable as it at first appears ; 

 inasmuch as I have shown, in my former volume, that the 

 Lepadidae can reject half digested food by their mouth, and 

 secondly, that the final stage of digestion appears to take 

 place in the upper part of the stomach. In the male of this 

 very species, as we shall immediately see, there certainly 

 is no mouth or stomach, and apparently no rectum or anus ; 

 so is it likewise with the males of Scatyellum vulgare and 

 ornatum : in Proteolepas, there is a mouth and an oesophagus, 

 but no stomach, rectum, or anus. There are, I believe, 

 no other known instances, in the whole great class of Crus- 

 tacea, of the absence of an anus. 



The stomach, in Alcippe, is much corrugated, so as to 

 be deeply pitted ; but there are no regular caeca. The 

 enveloping hepatic layer is thick, brownish, pulpy, and 

 formed of pellets of cellular matter, not distinctly arranged 

 in lines as is general ; there is the usual delicate muscular 

 layer. The stomach was in every case empty, and I did 

 not notice the separated epithelial coat, so generally found 

 in other cirripedes. 



Organs of Sense. — I failed in discovering the eye, which 

 I have no doubt exits, as it is conspicuous in the pupa and 

 in the male. The olfactory pouches are seated rather laterally 

 under the maxillae, as in Ibla. As in this same genus, the 

 acoustic sack is seated remarkably low clown (tig. 5), at 

 a very considerable distance beneath the basal articula- 

 tion of the first cirrus : the orifice is seated on a slight 

 prominence : the acoustic vesicle, I believe, is sub-cylindrical, 

 with irregular projections. I did not make out anything 

 distinctly on the nervous system. 



Female Generative System. — The animal we have thus 

 far described is exclusively female : when a longitudinal 



to Mr. Newport ('Annals of Nat. Hist.,' 1849, p. 277), the larvae of certain 

 parasitic Hymenoptera have a stomach without any anus. No crustacean, 

 according to Milne Edwards, is destitute of this orifice. 



