VELLETIA. 221 



In Velletia no part of the cross row of teeth is 

 straight ; its central part is much arched, and is com- 

 posed of the central tooth and twelve lateral teeth 

 on each side, which do not alter much in form ; then 

 comes one tooth of a diiferent form, and lastly six 

 more on each side, which latter are in a slight curve. 



99. 1. Velletia lacustris. Oblong Lake Limpet. 

 — Shell oblong, compressed, with the point 

 slightly recurved in an oblique direction and 

 nearly central, (t. 10. f. 126.) 



Ancylus lacustris. Muller, Vei-m. ii. 199.; Drop. p. 47. t. 2. 

 f. 25 — 27.; Sowerhy, Gen. f. 2.; Turton, Man. ed. 1. 141. 

 f. 126. — Patella lacustris. Montagu, T. B. p. 484.; Don. 

 B. S. t. 150. (not Linn.) — Patella oblonga. Lightfoot, 

 Phil. Trans. Ixxvi. (1786), 168. t. 2. f. 1. 5.; Turt.'Dict. 

 p. 138. — Crepidula oblonga. Fleming., Ency. — Ancylus 

 oblongus. Forbes and Hanley., B. M. iv. 188. t. 122. f. 5, ; 

 Clark, Ann. and Mag. N. H. xv. 278. — Patella cornea. 

 Poiret, Prod — Velletia lacustris. Gray, Man. 251. t, 10. 

 f. 126. — Acroloxus lacustris. Becli, Ind. 124. — Ancylus 

 Mocjuinianus. Bourg. Jour. Conch. 1853, 197. t. 6. f. 9. 



In still waters, attached to aquatic plants. 



Animal blackish. 



Shell a quarter of an inch long, and hardly a 

 tenth in breadth, extremely thin and transparent, 

 smooth, oblong, compressed at the sides, with the 

 apex pointed and near the centre of the shell, in- 

 clining towards the narrower end, and turning a 

 little obliquely towards the left side.* 



The egg cases are very depressed, orbicular or 



* Mr. Guilding {Zool. Journ. iii. 535.) has described two 

 West Indian species of this genus, which I have lately had the 

 opportunity of reexamining and proving to be true Velletice, 

 which was doubtful from Mr. Guiiding's erroneous description 

 of the animal. 



