Crustacea of St. Andrews. 343 



Fam. PaguridsB. 



Genus Pagurus, Fab. 



Pagurus hernhardus^ L. ; Bell, op. cit. p. 171. 



Everywhere abundant between tide-marks and in deep water. 

 A young specimen was lodged inside a fragment of a stalk of 

 wheat. 



This species has nine or ten branchige on each side, besides 

 a rudimentary organ at the base of the first pair of foot-jaws. 

 The latter have no branchial whips, and differ considerably 

 from those of the Brachyura. 



The first pair of foot-jaws have the inner division very much 

 elongated, almost antenniform, and bordered with long hairs, 

 while the external portion is small. In the next pair the inner 

 division more closely agrees with the external in length, and 

 the whole is not very different from the same part in Carcinus 

 mcenas minus the whip and branchia. The third pair is shorn 

 of its whip and large flap, and has the middle segment * repre- 

 sented by a narrow pedicle. The fourth pair has a narrow 

 shield turned over at the free edge, and, instead of the two 

 narrow spikes below, there is a flattened organ which forks 

 into a narrow and a broad flap at the tip. The fifth pair has 

 its inner division broad and flattened, and its outer small, but 

 widened at the tip ; the median division has a very regular ar- 

 rangement of bristles at its tip, which points or slopes inwards. 



The parasitic Peltogaster paguri frequently occurs on the 

 abdomen. 



Pagurus cuanensis, Thompson ; Bell, op. cit. p. 178. 

 Occasionally from deep water. 



Pagurus ididianus^ Thompson (?) ; Bell, op. cit. p. 180. 

 St. Andrews Museum. I cannot speak with certainty of 

 this form. 



Pagurus Icevis, Thompson ; Bell, op. cit. p. 184. 

 Occasionally in the stomach of the haddock. 



Fam. PorcellanidaB. 



Genus Porcellana, Lamarck. 



Porcellana platyclieles^ Penn. ; Bell, oj). cit. p. 190. 



Abundant under stones between tide-marks, especially in 



* Corresponding to </, fig. 3, Trans. Linn. Soc. vol. xxiv. p. 86. 



