200 HALF AN HOUR WITH SHELL-FISH. 



* 



other a bright, almost canary yellow. Both 

 these are too well-known to need any verbal de- 

 scription. The Nassas, Fig. 107, or " Dog Whelks," 

 Fig. 107 are common British shells, and of these 

 we have two species not difficult to meet 

 with, incrassata and reticulata. The for- 

 mer has a long spire, and a thick lip to 

 the mouth, whence its name. The latter 

 may be easily identified, being much 

 larger than the preceding, and having its 

 external surface crossed with reticulated 

 Nassa reticu- lines. The " Pelican's-foot " shell is one 

 possessing greater interest. In this 

 species (Aporrhais pespelicanj) the lip of the shell 

 is expanded, and then divided into claw-like pro- 

 cesses, the whole greatly resembling the webbed 

 foot of a water-fowl. The young undergoes a great 

 many changes before it arrives at maturity. In its 

 earliest condition there are no signs of an expanded 

 lip, so that in this stage it bears little or no resem- 

 blance to its parent. Another not uncommon shell, 

 especially on our southern coasts, is the little 

 European cowry (Cyprea Europea). It is, perhaps, 

 the most lovely of all our native shells, its delicate 

 warm pink and chocolate blotches enhancing the 

 transverse furrows which sweep aclross the shell, 

 and gently curve round each end, Fig. 108. The 

 mantle is so formed that it can invest the whole of 

 the shell. It is a beautiful little creature for the 

 aquarium, as the bright colours of the fleshy parts, 



