No. 4-] AMPHITHOE LONGLMANA SMITH. 177 



shed, remaining intact except at the lines just mentioned. The 

 moulting process takes several minutes at least and is accom- 

 panied by considerable muscular effort to get out of the old skin. 

 In the several cases in which I observed the process, Amphi- 

 thoe leaves its nest to divest itself of its skin, and I have never 

 observed a moult in a nest but always some distance away. 

 After moulting the animal is rather quiet and cannot easily be 

 enticed from its nest by food. I have observed several cases 

 in which death occurred during the moulting process. In one 

 case moulting was not completed for several days. The 

 specimen was observed August 17 with the head and tail ends 

 drawn partly out of the old case. The next day the head and 

 antennae were still not completely drawn out, but the rest of 

 the skin was kicked off. On August 21 it was still in the same 

 condition, the feeble beating of the pleopods giving evidence 

 of failing strength. On the next day it died, the head and 

 antennae still only partly extricated from their old covering. 

 In several cases the antennae were observed to become broken 

 off in the process of moulting, but I have seen no cases in 

 which other appendages became lost in this way. The anten- 

 nae are the appendages most liable to more or less complete 

 loss from other causes, but owing to the rapidity with which 

 these organs can regenerate this loss can produce only a 

 temporary inconvenience. The cast-off skins are found some- 

 times on the bottom, and often floating on the surface of the 

 water, and in a short time after they are shed become filled 

 with swarms of protozoa. 



TJie Seat of Smell. 



Much has been written concerning the seat of the olfactory 

 sense in the Crustacea, but most opinions on the subject have 

 been based on morphological instead of experimental evidence. 

 The work of May and Bethe affords good evidence that in the 

 decapod Crustacea the seat of the olfactory sense, or, as Bethe 

 prefers to call it, of chemoreception, is in the first antennae, as 

 analogy with the insects would lead one to suspect. The first 

 antennae are not, however, according to Bethe, the only seat 



