56 PECTINID^. 



have the fry attached to a rib of Rissoa parva, showing 

 that they remove from place to place, at least in the 

 earlier stages of growth. The hooded crow is very fond 

 of these scallops. It takes one from the tangle at low 

 water and carries it to the shore or a bank, on which it 

 drops its prey, watching with cunning patience until the 

 scallop opens its shell. It then quickly thrusts its 

 pointed and strong beak into the gaping valves, forces 

 them asunder, and devours the dainty morsel. Dead 

 and bleached shells are thus often found in places at 

 some distance from the sea, where crows had been feast- 

 ing. Without this explanation they might have been 

 mistaken for fossils. Specimens of the variety pur- 

 purea attain a considerable size. One of mine is 3^% 

 inches long and 3 inches broad. This species differs 

 from the younger state of P.pusio in being larger, and 

 in the ribs being much less numerous, and equal in size 

 instead of alternately large and small. Being free and 

 Of a regular shape at all ages, it is readily distinguish- 

 able from the adherent and distorted adult of the other 

 species. 



I fear that some of my conchological friends will be 

 terribly shocked at my innovation in uniting P. niveus 

 with P. varius ; but I feel constrained to take this bold 

 step, even at the risk of not being soon forgiven. I had 

 for a long time great misgivings on the subject; but it 

 was not until I had most carefully examined and com- 

 pared a multitude of specimens of both these so-called 

 species, collected from various and distant places, that I 

 was able to arrive at a satisfactory conclusion. The 

 only points of difference between P. varius and P. niveus 

 consist in the latter having a broader and flatter shell 

 with more numerous and delicate ribs, and in the colour 

 being white. All these characters are combined or 



