PATH XX 
DREISSENSIA (continued), 
Fies. 
1—1l1. WD. lanceolata (Sow.). (P. 110.) 
1—3. Crackers, Atherfield. 
1. Leckenby Collection, Woodwardian Museum. a, left valve; b, ventral— 
showing opening for byssus. 
2. Wiltshire Collection, Woodwardian Museum. a, right valve; b, ventral. 
3. Leckenby Collection. Right valve. 
4, Perna-bed, Atherfield. Wiltshire Collection, Woodwardian Museum. a, 
left valve ; b, interior of same. 
5. Upper Greensand, Shaftesbury. British Museum, No. 88,894. Left valve. 
6—11. Greensand, Blackdown. 
6. Wiltshire Collection, Woodwardian Museum. a, left valve; b, part near 
the umbo x 2; ¢, dorsal of both valves. 
7. Wiltshire Collection. a, right valve; b, ventral; c, interior of same. 
. Bristol Museum. The type of Mytilus prelongus, Sowerby. 
, 10. Wiltshire Collection. Left valves. 
11. Bristol Museum. One of the types of Mytilus tridens, Sowerby. a, right 
valve; b, antero-ventral. 
co 0 
Genus—Triconta, Bruguiere. 
12. T. dunscombensis, Lye. Cenomanian (Bed 11), Humble Point, Lyme 
Regis. Museum of Practical Geology (No. 6774). a, right valve ; 
b, dorsal + (227782) 
13. T. ornata, @Orb. Hythe Beds, Lympne. Museum of Practical Geology 
(No. 6771). Left valve. (P. 85.) 
14. J. crenulata, Lam. Cenomanian (Bed 10), Dunscombe. Mr. Meyer’s 
Collection. Left valve. (P. 82.) 
