170 — Dr, Marow's and Mr. RACRETT’S 
Walker Test. Min. Rar. f. 18. 
Schröter Flussconch. t. 5. f. 26, a.b. —— 
Montagu Test. Brit. p. 460. vign. 1. f. 78. H. cristata. 
Habitat in aquis dulcibus, rarior. Incola griseus, a dextro latere instruitur 
spiculo tentaculum mentiente, quod quoties testa exit exseritur, re- 
trorsumque aliquantum curvatur, et a latere sinistro crista pennacea 
branchiali insignitur. (Muller) — — 
Testa diametro 4i poll. subpellucida, pallide cornea, apice plano. Ges 
fractus levissime striati. detruis exacte circinata, anfractui vicino 
incumbens. 
First figured as British by Walker. Found by Mr. 
‘Boys, near Sandwich; and by Mr. Montagu, in the 
river Avon, and near Wedhampton, Wilts. 
2 | 
seoreatll T. testa depressa, subtus mde Say te anfractibus qua- 
tuor, apertura orbiculari. | 
Montagu Test. Brit. p. 439. t. 13. f. 5. 
Habitat in mari, rarior. 
. Testa diametro vix 1 lin. subpellucida, dilute brunnea, subrugosa. 47- 
... fractus sutura. conspicua, infimus cylindricus. Apertura subequalis, 
juxta anfractum dilatior. . Spira nulla. | * 
Testa T. cristato similis, sed minor, magis solidus et opacus, Apex magis E 
prominens. (Montagu)  - s ` z 
Found only by Mr. Montagu, i in "Cornwall and De- 
vonshire. 
50. | RES Canietiat, | t 
Clathrus. T. testa cancellata; turrita, exumbilicata ; ‘anfractibus | 
contiguis, levibus. Linn. Fauna Suecica, m. 2170. 
Syst. Nat. p. 1237. n. 631. Linn. Gmel. p. 3603. 
Rondel Test. 89. f. 5. | 
Bonann. Recr. 3. t. 111. 
Lister Conch. t. 588. f. 51. 
Rumph. Mus. t. 29. ropa 
Guglt. Test, HL! H. 
| Plane. 
