MALACOZOA. GASTEROPODA. SCUT1BRANCHIATA. 177 



1. Lottia virginea. Delicate Lottia. 



Shell ovato-elliptical, little elevated, thin, subpellucid, glossy, 

 smoothish, but with obsolete radiating striae and faint con- 

 centric ridges; the umbo pointed, nearer the anterior end, 

 being at about a third of the length ; the colour yellowish-grey, 

 whitish or dusky, with radiating bands of red ; the inside 

 smooth, glossy, purplish. Length about half an inch, breadth 

 a third less, height two-twelfths. 



Found by me and my daughter Anne, in August, 1842, on 

 the sands between the mouths of the Dee and the Don ; in 

 October, by Mr. Alexander Murray, at Fraserburgh. 



According to Mr. Alder, a falciform process, containing two 

 large vessels running on opposite sides through its whole 

 length, and crossed at right angles by smaller vessels forming 

 projecting rings, with the whole surface ciliated, is attached to 

 the branchial cavity. It is capable of great extension and con- 

 traction, and a free action from side to side of the cavity, and 

 may be seen emerging in a curved form on the right side of 

 the head. There is also "a dense fringe of filaments com- 

 pletely surrounding the cloak, and bearing a strong resemblance 

 both in position and appearance to the branchial fringe of 

 Patella," but placed nearer the margin, and instead of being 

 composed of flat leaflets, as in that genus, consisting of nearly 

 linear filaments of unequal length, with thickened ends. 



Patella parva. Mont. Test. Brit. 480. Patella virginea. Flem. 

 Brit. Anim. 287. Lottia virginea. Alder, Ann. and Mag. of Nat. 

 Hist. vi. 404. 



GENUS 2. EMARGINULA. SLIT-LIMPET. 



Animal conical or convex, oval or elliptical beneath, 

 covered by a univalve shell ; head with two short, conical 

 tentacula, bearing the eyes on large tubercles near their 

 base internally ; mouth proboscidiform ; foot very large, 

 oval, margined externally with tentacular appendages ; 

 mantle very large, with its margins replicate, widely 

 open in front, and also communicating by a fissure with 

 a corresponding slit in the shell ; two equal pectinated 

 branchiae ; intestinal aperture at the extremity of a 

 small tube opening into the respiratory cavity. 



Shell conical, with the aperture oval and wide, the 

 summit inclined backward ; a vertical notch or slit in the 



