20 BULLA. DIPPER. 



often a cliesnut shade, and visible all the way clown : length 

 two inches or more ; breadth one and a quarter. 



The animal is furnished with a strong gizzard, consisting 

 of two somewhat triangular thin smooth white testaceous 

 plates, nearly an inch in diameter, placed upon each other, 

 with an intervening thick tough yellowish ligament con- 

 necting them together : and within one of the lateral angles 

 placed on the ligament, is an elongated testaceous semi- 

 cylindrical hollow white additional plate. Fig. 3, 4. 



On the Devon and Cornish coasts $ and Dublin bay. i\ v. 



2. Bulla Hydatis. Paper Dipper. 



Montagu, Vignette 1. f. I, 2 Da Costa, pi. 1. f. 10 

 Donovan, pi. 88 Linn. Trans, ix. pi. 6. f. 1 Dorset Cat. 

 pi. 23. f. 10. 



Shell oval, thin, brittle, semitransparent, tumid, green 

 or yellowish, often covered with a thin chesnut-colored 

 skin, irregularly wrinkled transversely, and very finely and 

 Closely striate longitudinally, when young glossy and nearly 

 smooth : aperture large, contracting near the crown, which 

 is concave and without external volution : outer-lip very 

 thin and extending beyond the crown : inner-lip spread, a 

 little thickened, and whitish or chesnut-colored: length an 

 inch; breadth three quarters. 



The inhabitant of this shell is also furnished with a 

 Strong coriaceous blackish gizzard, of a triangular form, pr 

 consisting of three oval petal-like divisions, each with a 

 strong raised longitudinal rib down the middle, and about 

 twelve transverse ones. Montagu, Vignette 1. f. 5, 6. 



On the western coasts, Dunbar in Scotland, and the 

 strand at Balbriggan in Ireland, v. v. 



3. Bulla Akera. Elastic Dipper. 



Dorset Cat. pi. 22. fig. 13. 



Bulla resiliens. Donovan, pi. 79. 



Shell oval, transparent, membranaceous, elastic, pale 

 horn-color, often marked with brown spots or patches, 

 slightly striate longitudinally, whitish within: aperture 

 large, much contracted at top, which is obtuse, convolute 

 and channelled round the circumference, the volutions not 

 produced but fiat and even with the body ; outer-lip ex- 

 tremely 



