(SECT. D) r BALANUS CRENATUS. 261 



Animal's body unknown. 



Affinities. — In the basis being sometimes permeated towards the 

 circumference by pores, and by the colouring (the other species in this 

 and the next section being dirty white), B. patellaris has almost as 

 strong a claim to be ranked in the last as in the present section : in 

 the rounded summits of the radii, and in the state of the basis, it, 

 perhaps, shows more affinity to B. improvisus than to any other 

 species ; it is, however, almost equally allied to B. glandula. 



27. Balanus crenatus. PI. 6, fig. 6 a — 6g. 



B. crenatus. Bruguihe. Encyclop. Method, (des Vers) 1789. 

 Lepas eoliacea, var. a. Spengler. Skrifter af Naturhist. Selskabet, 



b. i, 1790. 



— borealis. Donovan. British Shells, PL 160 (1802-1S01). 



B. eugosus. Pulteneg(?) Catalogue of Shells of Dorsetshire, 1799. 



— Montagu (?) Test. Brit. 1803. 



— Gould (!) Report on Invertebrata of Massachusetts 



(1S41), fig. 10. 

 B. glacialis (?) J". E. Gray. Suppl. Parry's Voyage, 1819. 

 B. elongattjs (!), clavatus (!), Auctorum variorum. 



Shell lohite : radii with their oblique summits rough and 

 straight. Scutum without an adductor ridge : tergum with 

 the spur rounded. 



Hah. — Great Britain, Scandinavia, Arctic Regions as far as Lancaster Sound, 

 in 74° 48' N. (Mr Sutherland) ; Bearing's Straits (Captain Kellett) ; United 

 States; Mediterranean; West Indies, (Mus. Brit.); Cape of Good Hope, (Mus. 

 Ivrauss). Generally attached to shells and Crustacea in deep water; sometimes 

 to ships' bottoms. Very common. 



Fossil in glacial deposits of Scandinavia and Canada, Mus. Lyell ; in the 

 mammaliferous, and Red, and Coralline Crags, Mus. S. Wood, J. de C. Sowerby, 

 Bowerbank ; Miocene formation, Germany, Mus. Krantz. 



I find, in most collections, this species confounded with 

 B. balanoides ; I have even seen the two species, placed by 

 Leach, on the same tablet in the British Museum : B. ba- 

 lanoides is, moreover, generally confounded with Chtha- 

 malus stellatus ; nor has anyone hitherto separated the pre- 

 sent species from B. improvisus. On the other hand, trifling 

 varieties, both of B. balanoides and B. crenatus, have com- 

 mon ]y been considered as specifically distinct. From these 



