252 M. F, d'A. Furtado on Viquesnelia atlantica. 



little behind the right upper tentacle. Capreolus ? Flagel- 

 lum absent. Dart-sac absent. Accessory glands represented 

 by a glandular layer surrounding the vagina. Spermatheca 

 present. Shell rudimentary, concealed within the mantle, 

 ovalj depressed, with a rudimentary spire. 



Viquesnelia atlantica, Mor. & Dr. 



Viquesnelia atlantica, Mor. & Dr., Hist. Nat. des Azores, 1860, p. 139, 

 pi. i. fig. 1. 



Animal 25 millims. (1 inch) long, 3 millims. (| inch) 

 wide, elongate, compressed behind, narrowed towards the 

 middle behind the mantle, tuberculo-rugose, chocolate- 

 coloured to a greater or less degree in different individuals. 

 Mantle entire, defining by its posterior border the posterior 

 two fifths of the body, and almost as long as the tail when 

 the animal is fully extended, rounded in front, gibbous over 

 the shell (the place of which is indicated by a reddish patch), 

 finely shagreened, in some individuals with large blotches of 

 bluish colour. Neck about one fifth of the total length, thick, 

 rounded, slightly curved longitudinally, narrowed in front, 

 not exceeded by the foot, with large tubercles and two longi- 

 tudinal furrows which extend to the bases of the tentacles ; 

 external to these grooves are two rows of large quadrilateral 

 oblong tubercles ; colour dull reddish, deeper on the sides, where 

 it agrees with the ground-colour of the animal, brighter and 

 pinkish above, with large yellow blotches along the upper 

 part of each side. Locomotor surface narrow, parallel-sided, 

 with two grooves, of a general bistre or sepia-colour, with 

 minute dark spots, glistening. Tail much compressed, tole- 

 rably elevated, with oblique grooves intersecting so as to 

 form polygonal lozenge-shaped or hexagonal areas which are 

 raised and resemble plates ; each plate has very many black 

 shining elevations, which, when examined by a powerful lens, 

 are seen to be small hemispheres sharply defined and 

 resembling the eyes of a spider. At times the animal, wlien 

 beginning to creep, raises the tail considerably in a peculiar 

 way. Tentacles — the upper ones wide apart at the base, 

 strongly divergent, two thirds the length of the neck, cylin- 

 drical but insensibly tapering, with a shagreen-like surface, 

 deeply coloured, nearly opaque ; terminal tubercles incon- 

 spicuous, obliquely truncate above ; eyes very inconspicuous, 

 black ; the lower tentacles one quarter the length of the supe- 

 rior, brighter-coloured, much less divergent. Head with 

 anterior surface subvertical, rounded, furnished with large 

 tubercles. 



