PLATE CXLI. 



MYTILUS RUGOSUS. 



RUGGED MUSCLE, 

 GENERIC CHARACTER. 



The hinge toothless, and consists of a longitudinal furrow. 



SPECIFIC CHARACTER 



AND 



SYNONYMS. 



Shell rhombic oval, rugged, obtuse at the ends and antiquated. 



Mytilus rugosus : testa rhomboideo-ovali rugosa obtusa antiquata. 



Linn. Syst. Nat. p. 1156- No. 249. 

 Pholas noster, sive concha intra lapidem quendam cretaceum degens. 



List. II. An.. Angl. p. 1722. tit. 21. tab. 4. 



Mytilus parvus rhomboidea-ovalis, subalbescens, rugosus. Rugosus^ 

 Rugged, Da Costa Brit. Conch, p, 223. sp. 52. 



The Mytilus rugosus is rather a rare species on our coasts. Lister 

 notes it from Hartlepool in Durham, and Da Costa says on the coast 

 of Yorkshire, about Scarborough, Whitby, &c. It is found in incre- 

 dible abundance, niched or burrowed, in the rocks of lime-stone, 5cc, 



