144 MALACOZOA. GASTEROPODA. PECTINIBHANCHIATA* 



without longitudinal striuke, the pillar-groove white. Length 

 five-twelfths of an inch, breadth three-twelfths. 



It varies much in colour, and considerably in form, and 

 thickness. Sometimes it is of a uniform yellowish-grey ; rarely 

 reddish-grey or rose-colour; often with one broad purplish- 

 brown band, or with two broad brown, and two narrow white 

 bands ; or with three brown and four white bands. It has 

 accordingly been made into several species by authors. " In 

 all," as Dr. Johnston remarks, "the body whorl is obscurely 

 angulated near the base, and at the suture, which is made 

 more obvious by a whitish band winding up the spire." 



According to the same accurate observer, " The snail is of 

 a pale flesh-colour, the proboscidiform mouth reddish-orange, 

 the sides, and sometimes the head, dusky or black ; tentacula 

 setaceous, contractile, the eyes on short pedicles at their base ; 

 foot oval, rounded at both ends, widest behind, the anterior end 

 capable of being extended considerably beyond the head, the 

 margins plain, but there are two very short filaments between 

 the hinder part and operculum. It swims on the surface in 

 a reversed position, and it frequently leaves the water to settle 

 on the surface of fuci exposed to the atmosphere." 



On Fuci, near low-water mark, on the Kincardineshire 

 coast. On the Pier-head at Aberdeen. Abundantly on the 

 sandy beach between the Dee and the Y than ; where it is often 

 found alive on alga? ; found also on the coast from Cruden to 

 St. Fergus, by Mr. Alex. Murray. 



The principal varieties that occur with us are : — 



A. L. variabilis quadrifascidta, as described above. 



Turbo quadrifasciatus and yinctus. Mont. Test. Brit. 308. 

 Turbo quadrifasciatus. Flem. Brit. Anira. 299. — Lacuna quadri- 

 fasciata. Turt. Zool. Joum. iii. 192. — Lacuna vincta. Johnst. 

 Berw. Trans, iii. 270. 



B. L. variabilis bifascidta. Two-banded. 



Shell broadly ovato-conical, of four rapidly enlarging convex, 

 thin, pellucid whorls, which are faintly striated transversely, 

 and obscurely marked with undulated longitudinal striulas ; 

 the last turn very large, with two broad brown and two narrow 

 white bands, of which the two upper appear on the next turn ; 

 the mouth round, with the peristome thin and white ; a deep 

 broad groove from the umbilicus margined by the slightly re- 

 flected columellar margin. Length two-twelfths of an inch, 



