MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 127 



Plentiful off Aberdeen and Peterhead, at Gamrie and Banff; 

 sometimes cast on the beaches ; very frequently brought up on 

 the lines, but usually the shells only, containing Paguri. 



Natica glaucina. Var. B. Turt. Conch. Diet. Natica Alderi. 

 Forbes, Malacol. Mon. 31. Natica Alderi. Johnst. Berw. Trans, 

 iii. 266. 



4. Natica nitida. White Natica. 



Shell ovato-globose, rather thick, highly glossed ; with the 

 spire very short, and rather acute ; the turns five, faintly stri- 

 ated transversely, flattened toward the margin, so that those on 

 the spire are but slightly convex, with the suture inconspicuous ; 

 the last turn ventricose ; the mouth oblique, semicircular ; the 

 outer lip thin, forming at its junction an acute angle filled by 

 callus, the inner partly covering and narrowing the longitu- 

 dinally striated umbilicus with a mass of callus ; the colour 

 milk-white, with a band of more opaque white margining the 

 whorls, and another encircling the umbilicus. Length four- 

 twelfths of an inch, breadth three-twelfths. 



This species is very closely allied to Natica Alderi, from 

 which it differs in being less ventricose, with the spiral turns 

 flattened, and the colour white, without any markings. It 

 differs from Natica Mammilla in many respects. 



A single specimen found by me, in a fishing-boat, at Bod- 

 dam, near Peterhead, on the 5th of August, 1842. 



Nerita nitida. Donov. Brit. Shells. 144. Nerita nitida. Mont. 

 Test. Brit. Suppl. 149. Natica nitida. Flem. Brit. Anim. 319. 



5. Natica helicoides. Helicine Natica. 



Shell ovate, thin, covered with a delicate epidermis ; of four 

 turns, which are convex, separated by a canaliculate suture, 

 and obsoletely striulate transversely and longitudinally; the 

 spire short, convex, rather obtuse; the mouth oblique, ovate, 

 rather angulate anteriorly, the outer lip thin, the inner con- 

 tinued over the columella, but very thin, and leaving a narrow 

 fissure in the umbilical space, on which there is no callosity ; 

 the colour white, that of the epidermis yellowish-white. 

 Length four-twelfths of an inch, breadth a fourth less. 



The above description is taken from a specimen which I 

 found, on the 5th of August, 1842, in a fishing-boat, at Bod- 

 dam, or Buchan-Ness, near Peterhead. The shell is quite 

 perfect, and is identical with a fossil shell found by Mr. Lyell, 

 in the Norwich Crag. It has be?n described by Dr. John- 



