306 Mr Jenyns's Monograph on the 



with it ill the ditches about Battersea Fields, and in other parts of 

 Surrey. 



* * Testa distincte incequilaterali. 



Sp. 4. P. pulchellum, Nobis. — Tab. xxi. Fig. 1 — 5. 



P. testa oblique ovali, ventricosa, profundius striata ; umbonibus ob- 

 tusiusculis, simphcibus. — Fig. 1. 



Long, vix 2 lin. Alt. 1^ hn. Crass, l^lin. 



Var. fi.— Fig. 2, 3. 



Plerumque minor, testa tenuius striata; umbonibus subacutis. 



Long. If lin. Alt. 1^ lin. Crass. 1 lin. 

 Pera pulchella, Leach 3ISS. in Brit. Mus. 



Cyclas fontinalis, Brown in Edinb. Journ. of Nat. and Geog. Scien. 1. 

 11. PI. \.f. 5—7. — Alder in Trans. Nat. Hist. Soc. Newcast. 1. 41. 



Var. y. 



Testa oblique ovali, tenuiter striata, compressa, marginibus acutis. 



Long, l^lin. Alt. l^lin. Crass. J lin. 



Var. I— Fig. 4, 5. 



Testa, suboblonga, ventricosissima, profundius striata ; margine obtu- 

 sissimo. 



Long, l^lin. Alt. l£ lin. Crass. 1^ lin. 



Animal album, siphone polymorpho; cyhndraceo, conico apice truncate, 

 vel obconico; nunc abbreviato, nunc in tubum gracilem subelongatum 

 (pracipue in Var. <5.) extenso ; margine hie illic inciso, vel inte- 

 gerrimo. 



Testa quain maxime variabilis, in a, /3, et 7, obbque ovalis, distincte 

 inEequilateralis, nunc ventricosior, nunc compressiuscula, plus minusve 

 profunde striata, nitida, cinereo-lutescens, interdum autem sorde ferru- 



