140 MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 



marked with alternate dark brown and white lines, presenting 

 a tesselar appearance ; the aperture roundish, or somewhat 

 semicircular, with the margin thin, white spotted with brown, 

 the interior dark purplish-brown. Height two-twelfths of an 

 inch, breadth rather more. 



This is so nearly allied to Littorina saxatilis, from which it 

 differs only in not being so conical, in wanting the longitudi- 

 nal ridges on the turns, and in being less angulate beneath, 

 that I can hardly consider it distinct. 



It occurs abundantly on many parts of the rocky coast, from 

 Stonehaven to Peterhead, among Balani and in crevices, near 

 high-water mark. On the stones of the Pier-head at Aber- 

 deen, along with Turbo saxatilis. 



Dr. Turton, in dedicating this species to Mr. Bean, playfully 

 named it "fabalis ;" but as this would lead one to suppose the 

 shell to resemble a bean, and as Mr. Bean is not known abroad 

 by the name of Faba, I have given the specific name the usual 

 form. 



Turbo fabalis. Turt. Zool. Journ. ii. 366. PI. 12. f. 10.— Turbo 

 fabalis. Flem. Brit. Anim. 298. 



7. Littorina neritoides. Flat-topped Periwinkle. 



Shell subglobose, thick, with the spire depressed and round- 

 ed, the suture distinct, the last whorl extremely lai'ge, ventri- 

 cose, longitudinally striulate, transversely striate ; the mouth 

 roundish-ovate, laterally dilated, the outer lip thinned at the 

 margin, and forming an acute angle with the last whorl ; the 

 colour olivaceous brown, dusky, greenish, yellow, orange, 

 plain, banded, or chequered; the inside dusky, purple, pink, 

 yellow, or white. Length eight or nine-twelfths of an inch, 

 breadth six or seven. 



Very abundant on the rocky coasts, generally among fuci, 

 between the tide-marks : Stonehaven, Aberdeen, Collieston, 

 Peterhead, Gamrie, Banff, Portsoy. 



Turbo neritoides. Linn. Syst. Nat. 1232. — Nerita littoralis. Linn. 

 Svst. Nat. 1258. — Nerita littoralis. Penn. Brit. Zool. iv. 141. PI. 

 87. f. 143; Ed. n. 346. PI. 90. f. 3.— Turbo retusus. Lamk. Syst. 

 vii. 48. — Turbo neritoides. Lamk. Syst. vii. 48. — Nerita littoralis. 

 Flein. Brit. Anira. 318. — Littorina neritoides. Jobnst. Berw. Trans, 

 iii. 269. 



Genus 5. Turritella. 



Shell turrite, with the spire very elongated and taper- 

 g to a fine point, the whorls convex, longitudinally 



