310 TEST ACE A ATLANTIC A, 



Fam. 2. TESTACELLID-E. 

 Genus 2. PLECTROPHORUS, Ferussac. 



Plectrophorus Orbignii. 



Plectrophorus Orbignii, Fer., Hist. 11. 87. t. 6. f. 7 (1819) 

 Mouss., Faun. Mai. des Can. 7 



(1872) 



Habitat ' Teneriffam ' (sec. d'Orb. olim) ; sed mihi non 

 obvius. 



The present slug demands exactly the same strain on our 

 credulity as the Limax noctilucus does, for, like that species, 

 it was both described and figured (in 1819) in Ferussac's ' His- 

 toire Naturelle des Mollusques,' as Teneriffan, on the authority 

 of M. d'Orbigny, who nevertheless made no sort of allusion to 

 it in his subsequent Canarian catalogue issued in 1839! We 

 are almost driven therefore to conclude that d'Orbigny must 

 have had some particular reason for refusing admission to it in 

 the portion of Webb and Berthelot's publication which he 

 undertook to compile; yet since he ignores the subject alto- 

 gether, and the diagnosis still remains uncommented upon, and 

 uncancelled, in the great work of Ferussac, I scarcely see how 

 we can exactly pass it over, even though the silence of M. 

 d'Orbigny may appear somewhat ominous as regards its true 

 Teneriffan claims. 



The most salient character for which the P. Orbignii would 

 seem to be conspicuous (but which appears identical with the 

 main feature of the Testacellas) is the presence of a small 

 external Ancylus-like, crochet-shaped shell which is carried on 

 the hinder region of its body, at a short distance from the tip, 

 between which and the posterior edge of the shield there is a 

 rough dorsal band. The animal however is said distinctly to 

 possess a shield, which Testacella does not. 



G-enus 3. TESTACELLA, Cuvier. 



Testacella Maugei. 



Testacella Maugei, Fer., Tabl. Syst. 26 (1821) 



Lowe, Cambr. Phil. S. Trans, iv. 40 



(1831) 



Id., Proc. Zool. Soc. Lond. 163 (1854) 



Morel., Hist. Nat. des Acor. 143 (1860) 



Paiva, Mon. Moll. Mad. 6 (1867) 



Mouss., Faun. Mai. des Can. 11 (1872) 



Habitat Canariam Grandem, et Teneriffam ; in hortis cultis- 



