68 Rev. Canon Norman's Revision 



Distribiitiun. Bay of Biscay, ' Travailleur ' {Jeft'eys)) ; off 

 Azores, 450-1000 fathoms, ' Challenger' [Watson) ; Azores, 

 1287 metres [Dautzenherq) ; ' Blake,' Stat. 43, lat. 24° 8' 

 N., long. 82° 51' W., 339 f\ithoms [Dall) . 



Fossil. Middle Pliocene of Calabria {Segmnza). 



Mr. E. A. Smith has kindly, at my request, compared the 

 specimens of this species which are in the British Museum 

 with the figures and description of B. Guernei, Dautzenberg, 

 and has confirmed my expectation that the latter cannot be 

 regarded as specifically distinct from B. semilevis. It is clear 

 also, I think, that B. ehurnea, Dall, is the same thing. 



Genus 2. Haminea, Leach. 



47. Haminea hydatis (Linn.). 



Var. glohosa, Jeffreys. 



Genus 3. Acera, Miiller. 



48. Acera buUata, Miiller. 



Var. 1. nana, Jeffreys. Length ^rV inch. 

 Var. 2. Farrani, Norman. Length If inch. 



Akera buUata, var. gigantea, Norman, IMuseum Norman- 

 iauum, iv. Mollusca, 1888, no. 101. 



The variation in size in this species is most extraordinary, 

 and perhaps the forms here treated as varieties should rather 

 be regarded as entitled to rank as species. The full size of 

 ordinary specimens may be taken as an inch ; but no speci- 

 mens of var. nana, which was dredged by Jeffreys and 

 myself in shallow water at Balta Sound, Shetland, exceed 

 three twentieths of an inch. On the other hand Dr. Farran 

 ibund many years ago (see Nat. Hist. Review, vol. iv. (1857) 

 p. 74) the gigantic variety which I here name after him. 

 The specimens were dredged near Birterbuy Bay, Ireland : 

 the animal measured 3 inches long and 2^ wide, and 

 weighed 2^ ounces. The shell of one of these giants, now 

 in my collection, measures If inch long and an inch wide ; 

 hundreds of specimens of var. nana might be placed in 

 it as in a box! In 1876, in company with my friend Mr. 

 David Robertson, 1 dredged diligently the spot carefully 

 described by Farran, but without again meeting with this 

 form ; but Mr. A. G. More informed me that the year before 

 that just mentioned he had found a similar-sized specimen in 

 a lough nearer Galway. 



