GONCHOLOGY. 



95 



Bivalves. First figured by Pennant. Found in England on the 

 ^■"'"Y""" *" British and Devonshire coasts, and at Falmouth in 

 Cornwall. In Scotland in the Frith of Forth, Cromar- 

 ty and Zetland. 

 Minima, ]2. Minima. Shell sub-orbicular a little compressed, 



flesh coloured, and glossy with broad concentric striae ; 

 from the beak two white lines, in shape like the letter 

 V, run half way down the shell ; umbo prominent, 

 pointed, and a little turned to one side ; inside glossy 

 white; margin plain; length a quarter of an inch; 

 breadth rather more. 



Test. Brit. tab. 3. fig. S. 

 Dredged up at Falmouth harbour by Mr Montagu. 

 Subeorda- 13. Subcordata. Shell white, cordate, with strong 

 :a, longitudinal costated striae, with remote transverse 



ridges, making the depressions between in the shape of 

 a long square ; beak nearest one end, incurvated ; an- 

 terior side almost straight and much sloping from the 

 beak ; margin subcrenated ; diameter a quarter of an 

 inch. 



Test. Brit. tab. 3. fig. 1. 

 Found by Mr Montagu in sand from Falmouth har- 

 bour. 

 Branulata 14i. Granulala. Shell thick, sub-orbicular, strongly 

 reticulated, of a white colour, with spots and streaks of 

 a brown colour ; umbo much turned to one side, be- 

 neath which is a cordiform depression ; margin crena- 

 ted ; length seven-eighths of an inch, breadth one inch. 

 Brit. Shells, tab. 83. 

 Found at Cornwall ; Mr Donovan. At Falmouth 

 harbour by Mr Montagu. 

 Deflorata, 15. Dejlorata. Shell oblong, sub-oval, thin, tinged 

 with purple, with undulated longitudinal stria? and a 

 few transverse wrinkles ; beak placed a little to one 

 side, not very pointed ; hinge with two teeth in each 

 valve ; length an inch, breadth an inch and three quar- 

 ters. 



Brit. Zool, tab. 51. fig. 51. 

 Test. Brit. tab. 3. fig. 4. 

 First described as British by Pennant. Found at 

 Falmouth by Mr Montagu. 

 -)ecu:sata, 16. Decussata. Shell sub-rhomboidal ; strongly reti- 

 culated ; cut off diagonally at the anterior end, at which 

 part it is most strongly reticulated ; umbo nearest to 

 one end, apex turned to one side, beneath which is a 

 slight lanceolate cordiform depression; hinge with 

 three teeth in each valve, one of which is small, and in 

 one valve is almost obsolete ; length two inches, breadth 

 three inches. 



Brit. Zool. tab. 57. fig. 53. 

 Brit. Shells, tab. 67. 

 Lin, Tra?is. vol. viii. tab. 2. fig. 6. 

 Common on many parts of the coast. 

 r'ullastra, 17- Pullaslra. Shell resembles the last in shape, 

 longitudinal striae fine with concentric wrinkles ; cica- 

 trix broad and divided from the border ; length about 

 an inch and a quarter, breadth two inches. 

 Lin. Trans, vol. viii. tab. 2. fig. 7. 

 Lin. Trans, vol. vi. tab. 17- fig. 13, 14. (Wood.) 

 First separated from the preceding by Mr Wood. 

 Common on the English and Scottish coasts. In De- . 

 vonshire it is called pu/lit, and in Zetland cnllcock. 

 >er. f orans, . 18. Perforans. Shell sub-rhomboidal, concentrically 

 striated ; running into strong wrinkles at the anterior 

 side ; umbo near one end, and turned a little side- 

 wise ; hinge with three teeth in each valve, one of 

 which is small, the others long slender, and curve out- 

 wards ; length three eighths of an inch, breadth five 

 eighths. 



Test. Brit. tab. 3. fig. 6. Bivalves. 



Discovered by Mr Montagu burrowed in limestone S T~""' 

 at Plymouth. It is likewise found in several places on 

 the Scottish coast. 



19- Virginea. Shell strong sub-oval, transversely Virginea, 

 striated, interrupted in a few places by a deeper fur- 

 row ; umbo placed much to one side, beneath which is 

 a lanceolate cordiform depression ; hinge with three 

 teeth in each valve, the outer ones diverging, middle 

 ones bifid ; margin plain, edge obtuse ; length an inch 

 and a half, breadth two inches. 



Brit. Zool. tab. 55. fig. without number. V. . 



rhomboides. 

 Lin. Trans, vol. viii. tab. ii. fig. 8. 

 Common on the English coasts. The specimen from 

 which the above dimensions were taken we found in 

 Zetland. 



20. Aurca. Shell subcordated, moderately strong, Alirea, ., 

 rounded at both ends like the last, striated transversely, 



and marked with faint longitudinal striae ; umbo placed 

 near to one end, small pointed, turned to one side, with a 

 cordiform depression ; valves concave ; hinge furnished 

 with three teeth in each valve, the middle one bifid ;■ 

 length commonly about an inch, breadth an inch and 

 three eighths. 



Brit. Zool. tab. 67. fig. 34-, Telliiia rugosa. 



Lin. Trans, vol. viii. tab. 2. fig. Q. 



Pult. Dorset, tab. 13. fig. 3, V. Nebulosa. 

 On the English shores frequent ; found likewise by- 

 Mr Laskey in the Frith of Forth. 



21. Sulcata. Shell sub-triangular, smooth, obsolete Sulcata* 

 wrinkles ; umbo very prominent and large, turning a 



little to one side, beneath which is a lanceolate cordi- 

 form depression; cartilage slope depressed; margin cre- 

 nated ; hinge in one valve of three teeth, the middle one 

 much larger than the others'; length seven-eighths of an . 

 inch, 



Lin. Trans, vol. viii. tab. 2. fig. 2. - 

 From the north of Scotland. (Mr Swainson.) 



22. Triangularis. Shell strong, sub-triangular, yel- ; ''frianeu- 

 lowish-wliite, with a few obsolete concentric ridges ; i ar ; s ° 

 umbo central, prominent, and turned a little to one 



side ; each side slopes nearly equal ; a lanceolate cor- 

 diform depression ; hinge in one valve furnished with 

 two strong teeth, one running backwards parallel with 

 the cartilage slope, bifid; margin plain; length half . 

 an inch, breadth nearly the same. 



Test. Brit, tab, 17. fig. 3. \ 

 Found by Mr Montagu on the coast of Devon. 



23. Spinifera. Shell sub-triangular, with numerous- g D ; n ;f. ra 

 concentric equidistant ridges at the anterior end, be- 

 coming confluent, and forming short obtuse reflected 



spires ; beak central, and turned a little to one side ; 

 hinge with a single primary tooth, and a small cavity 

 on each side receiving two teeth from the opposite 

 valve ; margins plain ; length half an inch, breadth a ,. 

 little more. 



Test. Brit. tab. 17. fig. 1. ' 

 Discovered by Mr Montagu in a heap of sand from 

 Salcomb-bay, Devonshire. 



24. Re/lexa. Shell sub-orbicular, with thin laminal Reflex?., 

 reflected ridges, and fine longitudinal striae; hinge fur- 

 nished with three strong teeth in each valve, the middle 



one of which is sub-bifid ; margin finely crenulated ; 

 diameter about an inch. ' 



Mem. Wer. Soc. vol. i. tab. 8. fig. 1. 

 Discovered in the Frith of Forth by Mr Laskey. Mr 

 Montagu has found it on the coast of Devon. 



25. Orhiculala. Shell white, depressed, orbicular> Orbiculata, 



