APLYSIA. 5 



1. Aplysia puncta'ta*, Cuvier. 



A. punctata, Cuv. Annales du Museum (1803), ii. p. 295, pi. i. f. 2-5. 

 A. kybrida, F. & H. iii. p. 554, pi. cxiv. f. f. 4, and (animal) pi. YY. f. 1 . 



Body extremely flexible, brown of various shades, with a 

 tinge of purple, usually marked with black and white round 

 spots (some of which are arranged in star-like clusters, or the 

 spots become minute specks), and finely marbled or tessellated 

 by dark lines : mantle folded inwards on the back to admit 

 water into the gills : head extensile, having a tentacle-shaped 

 flap at each corner, which hangs downwards : mouth capacious, 

 with large lips: tentacles cylindrical, rather long and thin, 

 resembhug the ears of a hare, of a darker colour towards their 

 tips : eijes small, partly imbedded in the skin, so as to give the 

 appearance of their being encircled with a white iris : foot very 

 large ; the lower part is narrow, rounded in fi'ont and bluntly 

 pointed behind ; dorsal lobes sometimes raised into a hump, 

 with their edges of a paler hue ; sole light yellowish-brown : 

 male organ curved, on right-hand side. L. 4-6. 



Shell triangular, with a small apex and a broad base, convex 

 and sometimes gibbous, homy, rather thin, opaque and glossy : 

 inner layer firmly united with the outer layer and containing 

 but little calcareous matter except in aged specimens : sculp- 

 ture, several slight and irregular lines, which radiate from the 

 apex to the outer edge ; there are also numerous microscopic 

 and scratch-like longitudinal lines and very minute and close- 

 set concentric striae, besides the usual marks of growth : colour 

 yellowish-brown or tawny, sometimes dark reddish-brown : 

 spire exceedingly small, concealed by a thick deposit from the 

 hinder lobe of the mantle, representing an obliquely recurved 

 or involute apex : mouth occupying the whole of the under- 

 side ; dorsal margin gently curved and sometimes forming a 

 shoulder on a level with the apex or raised above it : inner 

 margin, on the opposite side, short and more or less incurved ; 

 front margin dilated and rounded ; all the edges are mem- 

 branous and fold back in the dried shell. L. 1-15. B. 0-85. 



Habitat : Laminarian zone, among seaweeds, on 

 every part of the British and Irish coasts ; occasionally 

 between tide-marks. It is generally distributed thi'ough 



* Spotted hke dice. 



