296 MR. E. A. SMITH ON THE [Apr. 1, 



F. arcuata, Sow., may also be forms of it. The distribution and 

 synonymy is given by WeinkaufiP (Conch. Mittelm. vol. ii. p. 394). 

 The specimens collected by Mr. ^lelliss were named F. arcuata. 

 Sow., by Jeffreys \ but in sculpture they more nearly resemble the 

 typical form of F. gibberula. In F. arcuata the costae are very 

 closely approximated to one another. Young specimens, in which 

 the capuliform apex has not been absorbed, have the appearance of 

 the genus Puncturella. 



Patella plumbea, Lamarck. 



Patella plumbea, Reeve, Conch. Icon. pi. iii. figs. 5 a-h. 



Patella cterulea, Quoy & Gaimard, Voy. Astrolabe, Moll. vol. iii. 

 p. 342, pi. 70. figs. 4-6. 



Patella cyanea. Lesson, Voy. Coquille, vol. ii. p. 417. 



Patella oaneseens, Reeve, op. cit. pi. 34. figs. 103 a-b. 



Hab. St, Helena (Q. Sf G., Lesson) ; Senegal {Lamarck). 



If, as I am inclined to believe, P. canescens be a variety of this 

 species, it shows that it is a very variable form. A considerable 

 number of very young shells were collected by Capt. Turton, which 

 probably are the early stages of different varieties of this species. 

 They are extremely variable iu colour, but it is impossible to distin- 

 guish them on that account alone. 



WiLLIAMIA GUSSONII (Costa). 



Ancylus gussonii, Costa, Cat. Test, due Sicil. pp. 120 & 125. 



Patella pellucida, Philippi, Moll. Sicil. vol. i. p. Ill, jd. 7. fig. 7. 



Patella gussonii, id. 1. c. p. 25.T, vol. ii. p. 84. 



Patella radiata. Pease, Proc. Zool. Soc. 1860, p. 437. 



Hab. Some parts of the Mediterranean, Madeira, Canary Islands, 

 Ascension Island. 



The specimens from St. Helena and Ascension Island are precisely 

 similar, and agree exactly with the shells in Cuming's collection 

 marked Patella radiata. Pease, and which, I presume, are the types 

 described, and supposed to have come from the Sandwich Islands. 

 Examples from the Canaries have the apex more excentric than the 

 majority of St. Helena specimens, and they are less distinctly 

 rayed. " The radiating ribs mentioned by Pease are very indistinct. 

 In his list of shells collected by Mr. Melliss at St. Helena (Ann. 

 Mag. Nat. Hist. 1872, vol. ix. p. 264) Jeffreys has quoted this 

 species under the name of Tectura virginea, ^Miiller. The latter 

 species, however, I believe is quite distinct. 



Bulla striata, Brugniere. 



Hab. Mediterranean, West Indies, Brazil, West Africa. 



With this species I unite B. media and B. adansonii, Philippi, 

 respectively from the West Indies and West Africa. I do not think 

 the slight differences pointed out by Philippi possess more than 

 varietal value. I have seen specimens from both localities with the 

 superior as well as the inferior striae. 



' Ann. & Mag. Nat. Hist. 1872, vol. is. p. 204. 



