Mollusca from the Xorth-icest Falklands. 129 



Mytilus magellanicus, Cliem. 



Mi/tilus magellamcus, Chem. Conch. Cab. viii. pi. Ixxxiii. fig. 742 ; 

 -Keeve, Conch. Icon. x. pi. vi. fig. 22. 



Roy Cove Creelc. 



One specimen .shows a curious graduated malformation, 

 b^'ing unusually incrassate in the centre of each valve. 



Brachyodontes (^Ilormomya) hlakennns, sp. n. 

 (PL VII. fios. 4, 4a.) 



B. testa alba, lata, epidermide sordide brunnea partim induta, ovato- 

 triangulari, parva, baud multum tumescente, postice leniter 

 rotundata, antice apud umbones acuminata ; mox expansa, super- 

 ficie undique radiatim irregulariter filolirata, iuterstitiis sub lente 

 arete spiraliter striatulis ; periostraco imbricate, margiuem super- 

 impendeute, pagiua intus alba, marginibus circa crenulatis, septo 

 minimo. 



AJt. 5, lat, 8 mm. 



Roy Cove. 



In form, and to some extent in sculpture, like a small 

 Br, cubitus, Say, and, with this, we consider it should be 

 placed in the subgenus Hormomya^ Morch. We would refer 

 to an exhaustive paper on the classification of the Mytilidse 

 by Mr. A. J. Jukes-Browne, F.R.S.* 



At Mr. Vallentin's request we name this shell in honour of 

 Mr. Robert Blake, Chairman of the Directors of the Falkland 

 Islands Company, who evinced much interest in the scientific 

 work and aided it by all means in his power. 



Modiolarca exilis, H. & A. Ad. 



Modiolarca exilis, H. & A. Adams, P. Z. S. 1853, p. 435 ; E. A. Smith, 

 Phil. Trans. RojalSoc. Lond. vol. clxviii. p. 190, pi. ix. fig. 24 (1879). 



Fox Bay, after a severe shore-gale. 



Modiolarca trope zina (Lam.). 



Modiola trapezina, Lamarck, Anim. sans Vert. vol. vii. p. 24 ; Delessert, 

 pi. xiii. fig. 7. 



Roy Cove, 2-4 fathoms; Crooked Inlet, at low water, 

 widely distributed. 



• Proc. Malac. Soc. Lond. 1905, pp. 211-224. 

 Ann, dc Mag, N, Hist. ider. 8. \ oL xiii. 9 



