OOPELTA. 225 



decided suspicion on the species whether as regards its Cana- 

 rian origin or the truthfulness of its diagnosis. Moreover it is 

 not said by whom the species was captured ; for, as it was pub- 

 lished in 1819, it clearly could not have been by d'Orbigny 

 himself whose sojourn in the Canarian Archipelago did not 

 take place until 1826." 



" The great distinctive feature of this slug a feature which, 

 if true, would certainly entitle it, as Mousson has well observed, 

 to generic separation consists in the fact of its being supposed 

 to possess a mucous disk on the hinder edge of its shield, which 

 has the power of emitting a strong phosphorescent light." 

 Wollaston, Testacea Atlantica, 309. 



P. NOCTILUCUS, d'Orb. (in Ferussac). PL 55, fig. 4. 



Body thick, broad ; hinder part of mantle with a marginal disk 

 formed of part of the mantle, which is lucid green and phosphor- 

 escent in the dark ; tail rounded ; respiratory orifice somewhat 

 anterior. Shell thick, oval, white, nearly transparent, smooth 



above, crystalline beneath. 



Teneriffe. 



Genus OOPELTA, Morch, 1867. 



0. NIGROPUNCTATA, Morcll. 



Shield with rounded black dots disposed in a double or 



quincunx order. Length, 1 inch. 



Guinea. 

 Unfigured. 



15 



