THE EUEOPEAN SEAS. 



115 



At Cascaes Bay, south of the Rock of Lisbon, 

 Mr. Mac Andrew dredged one of the most interesting 

 and peculiar members of the Lusitanian fauna, viz. 

 the Cymba olla, the only volute shell found in the 

 European seas, and one of the largest of our mol- 

 lusks. It was taken alive on a bottom of hard sand 

 at a depth of from 15 to 20 fathoms. It ranges 

 to low-water mark, and occurs abundantly in the 

 south of Portugal. This beautiful mollusk is of a 

 strikingly tropical aspect ; it does little more than 

 just enter the Mediterranean (I have picked up a 

 dead young specimen as far as the shore of Algiers), 

 and is abundant on the north-western coast of Africa, 

 to which region (the Senegal province) it probably 

 most strictly appertains. Out of a large list of 

 shells obtained at Faro the following may be se- 

 lected as strikingly marking the character of the 

 region : — Petricola lithophaga, Panopcza Aldrovandi, 

 Psammobia (rugosa-like species), Urvilia castanea, 

 Mactra helvacea, Gardium rusticum, Mytilus mini- 

 mus, Solecurtus strigillatus, Bornia corbuloides, JVa- 

 tica intricata and Guilleminii, Phasianella interme- 

 dia, Trochus Laugieri and canaliculars, Turbo ru- 

 gosus, Gerithium vidgatum, Murex corcdlinus, trun- 

 culus, Brandaris, and Edwardsii, Triton variegatum, 

 corrugatum and cutaceum, Purpura hcemastoma, 

 Cassis saburon ? Columbella rustica, a large yellow 

 Mitra, and Gonus Mediterraneus. Out of 99 species 

 enumerated, 59 or 60 are British species, but all, 



