Hinges of BritiJIj Bhahe Shells. 175 



Fig. 13, 14. The hinge of the Dovax Trunculm. 



15,16. The fame magnified, (a) A thick falcated tooth received, 

 when the fhell clofes, between (b. bl. (c c) Marginal 

 teeth. 



Tab. XVir. 

 I, 2. Venus ijlandica. (a) The great tooth which locks between 

 (b. b), while the rugged tooth (c) fits into r. hollow 

 within the fmall tooth (d). (c. e. e) Remote teeth. 

 3, 4. Fenus Chionc. Befides the two ftrong teeth in this fhell, 

 (a) and (b), there is a third, (c), which paffes into the 

 cavity (d). (e) A tooth grooved longitudinally. 

 5, 6. Venus verrucofa. (a. b) Two thick teeth receiving (c) be- 

 tween them, (d) A large tooth which paffes on the in- 

 fide of (e). (f ) A thin tooth in the direftion of the car- 

 tilage. 

 '],%. Venus Galllna. (a.b) The two principal teeth, (c.d) Two 

 fmaller ones, of which (d) is plate-like, (e) A marginal 

 tooth. 

 9, 10. Vetius exdeta. (a) An erea tooth which locks between 

 (b. b). (c) A thick channelled tooth received be- 

 tween (d. d). 

 II, 12. Venus decujfata. (a) The two cleft teeth in one valve, 

 (b) The fan-e in the oppofite. (c) The plain tooth. 

 13, 14. This ihell is provided with a beautiful peiSlinated hinge, 

 confifting of three teeth in each valve. Thefe teeth 

 are placed in the mod regular order, and the mid- 

 dle one, I believe, is conftantly grooved. Frequently 

 there is a channel in one of the other teeth, and fome- 

 times, though rarely, we meet with it in both. 

 When this fpecies is found with only two teeth in one 

 8 valve 



