PLATE CXLI. 



MYTILUS RUGOSUS, 



RUGGED MUSCLE, 

 GENERIC CHARACTER, 



The hinge toothless, and consists of a longitudinal furrow. 



SPECIFIC CHARACTER 



AND 



I 



SYNONYMS. 



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



Mytilus rugosus : testa rhomboideo-ovali rugosa obmsa antiquata. 



Linn. Si/st. Nat. p. 1156- No. 249. 

 Pholas noster, sive concha intra lapidem quendam cretaceum degens. 



List. II. An.. Angl. p. 1T22. tit. 21. tab. 4. 



Jig. 21. 

 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, &c. 



h 3 



