MALACOZOA. GASTEROPODA. PECT1NIBRANCHIATA. 125 



GENUS 1. NATICA. LAMK. 



Animal elongated, or oval, spiral ; head broad, with 

 two flattened tentacula ; mouth with two unequal lips 

 and a short proboscis; foot very large, thin, bilobate 

 anteriorly ; mantle enveloping a portion of the shell. 

 Operculum horny. 



Shell globose, or oval, spiral, umbilicate ; the aper- 

 ture entire, roundish, semicircular, or obovate ; the 

 umbilicus narrowed, and sometimes covered by callus, 

 the outer lip thin, internally even. 



1. Ndtica monilifera. Beaded Natica. 



Shell globose, rather thick, glossy; with the spire very 

 short and convex ; the suture deep ; the turns five, very con- 

 vex, faintly striate transversely, the last turn ventricose ; the 

 mouth oblique, semicircular, the outer lip thin, the inner cover- 

 ing but not narrowing the spirally grooved umbilicus with a 

 mass of white callus ; the colour brownish-yellow, reddish- 

 yellow, or pale greyish-purple, with a series of dark purple 

 spots near the upper margin of each turn, and four additional 

 series, often obliterated, on the last ; the base of the shell 

 white ; the inside white or tinged with red. Length an inch 

 and a fourth, breadth somewhat less. 



Young individuals are of the same convex form, but less 

 glaucous, being banded on a flesh-coloured or yellowish-red 

 ground, with five series of brownish-red or reddish-purple spots. 

 The red markings vary in form, but are generally linear and 

 oblique. Frequently they are all obliterated, excepting the upper 

 series ; but in young shells they are generally distinct. The 

 umbilicus is obscurely spirally grooved, and is sometimes not 

 intruded upon by the callus, but more commonly is partially 

 covered by it. 



Not very common on the beach at Aberdeen, after storms. 

 Found also about Peterhead. 



Cochlea rufescens, fasciis maculatus. Lister. Anim. Angl. 163. PI. 

 3. f. 12. Nerita glaucina. Penn. Brit. Zool. iv. 140. PI. 87. f. 141 ; 

 Ed. 2. PI. 90. f. ]. Nerita glaucina. Mont. Test. Brit. 469. 

 Natica glaucina. Flem. Brit. Anim. 319. Nalica monilifera. 

 Lamk. Syst. vi. 2, 200. Ed. n. vii. 636. Natica monilifera. Johnst, 

 Berw. Trans, iii. 265. Natica monilifera. Forbes. Malac. Mon. 30. 

 L2 



