388 Mr. Jerrreys on the Testaceous Pneumonobranchous 
IE 
D deel minor, albida, striis rarioribus.. Seu 
rata, tenuis, nitida, diaphana, glabra, alba. Anfractus 
4 vix 5, convexiusculi. Apertura subrotundo-rhom- - 
boidea: peristomio vix soluto. 
Long. 0.05.— Diam. 0.175. 
Found with the last; though much less common. It is a 
much more depressed shell than the Pl. albus, of a white 
colour, more polished and transparent, and is destitute of 
any markings. ‘The upper side is uniformly more even, 
and the under exceedingly concave. 
IMBRICATUS. 
Animal grisescens. Tentacula longa, flexilia, acuminata. 
Testa depressa, supra planior, subtüs convexiuscula, um- 
bilicata, tenuis, pellucida, transversim imbricato-stri- 
ata, fulva, epidermide fusco lamelloso induta. An- 
. fractus vix 3; ultimo in carinam obtusam obliquante. 
Apertura subrotundo-rhomboidea : peristomio soluto. 
Long. 0.015.— Diam. 0.1. 
Planorbis imbricatus. Müll. Verm. 2. p.165. Drap. 
Hist. des Moll. p. 44. t. 1. f. 49—51. 
| Turbo nautileus. Linn. Syst. Nat. 1. p. 1241. Gmel. 
— Syst. Nat. 1. p. 3612. 
Bc nautilea..- Ment. Test. Brit. p. $54. t. 25. f. 5. 
Planorbis cristatus. Drap. l. c. 
On the Iris Pseudacorus (on the decising lese of which - 
the animal feeds), in pools and ditches, in the autumn ; but 
ce Dot common. 
12. Tae E- = = 
| Animal nigrum. Pasaka latum. 
Testa 
