136 REPORT — 1856. 



Chiton cancellatus, Sav. — Is more nearly allied to C. Bissoi of the Mediter- 

 ranean than to C. asellus, of which it has been supposed to be a variety. 

 Chiton fulvus, Wood. — This fine species differs as much in its habits as in 

 ajipearance from its European congeners. It enjoys greater powers of 

 locomotion than any other Chiton of my acquaintance, creeping freely 

 in the sand between tide marks in Vigo Baj% where it is very abundant, 

 and where several were found adhering to the chain cable every time 

 it was raised from our anchorage abreast of the town of Vigo. It is, 

 nevertheless, extremely local, not recorded to be obtained in any locality 

 but those I have named, unless from Patagonia, whence there are spe- 

 cimens in the British Museum under another name, but in no way to be 

 distinguished from the present species. 

 Chiton Cajetanus, Poll. — Inhabits the Mediterranean and Bay of Biscay, but 

 has not been detected in any intermediate locality, nor on the south 

 coasts of Spain. 

 Patella vulgata, Lin. — Becomes a local species on the northern coasts of 



Norway, and I did not meet with it in Finmark. 

 Patella pellucida, Lin. — The distribution of this species is regulated by that 

 of the Laminaria, on which it feeds. It is not unfrequent in the north 

 of Spain ; is absent from the south of Spain and Mediterranean, but 

 unexpectedly appears again in the harbour of Mogador, where it is of 

 small size. In high northern latitudes it is much paler in colour. 

 Patella Gussonii, Phil. — Among some hundreds of dead specimens I only 



took one or two living, and these were upon a deep-water red fucus. 

 Calyptrsea Sinensis, Lin. — I have never obtained British specimens in less 

 than 8 or 10 fathoms, whereas on the coasts of Spain it is generally 

 found about the sea margin, and in shallow water. 

 Trochus crenulatus, Phil. — I believe to be specifically distinct from T. exi- 

 gutis, is subject to great variation in colour ; the grey variety is more 

 common to the eastward. 

 Trochus millegranus, Phil. — Of this species there are two very distinct 

 varieties, of which the smaller and more conical inhabits the Mediterra- 

 nean and south coast of England and Wales, while the larger is common 

 to the north-west coasts of Britain and Norway. 

 Rissoa abyssicola, Forbes. — A specimen received from Captain Spratt, 



dredged by him in 3,50 fathoms, about 40 miles from Malta. 

 Turritella communis, Risso. — The ordinary British form is wider in propor- 

 tion and possesses fewer volutions than that of the Mediterranean. A 

 large variety with numerous volutions is found in Cork Harbour and in 

 Bressa Sound, always in shallow water, while the ordinary variety in- 

 habits all the zones of depth. I have taken white specimens of both 

 the forms, consequently absence of colour is not always the consequence 

 of great depth. 

 Couus Mediterraneus, Brug. — Is very frequent at Lancerotte, but does not 



extend westward to Teneriffe or to the Salvage or Madeira Islands. 

 Purpura lapillus, Lin. — Though generally littoral, inhabits the depth of 8 or 

 10 fathoms in certain localities, and in these cases undergoes consider- 

 able modification of form; from deep water and mud, it is large and 

 fusiform, from 8 fathoms and rough ground the specimens are beauti- 

 fully imbricated. 

 Ringicula auriculata, Menhe.—Ki Vigo, the northern limit of its range, it 

 attains the greatest dimensions and is very abundant, but not striated as 

 in the Mediterranean and Madeira. 

 Nassa trifasciata, A. Adams. — Most abundant at Vigo, but smaller than in 



