400 TEST ACE A ATLANTIC A. 



Auricula bi color. 



T. elongate ovato-fusiformis, sensim irregulariter striatula, 

 subtenuis, nitidula, pallide cornea sed plus minus distincte 

 (prsesertiin in spira) purpureo-obscurata ; spira exserta, acuta, 

 nucleolo soepius albido et plus minus eccentrico ; anfractibus 

 8-9, convexiusculis, sutura impressa; apertura elongata, plicis 2 

 subalbidis (supera magna, intrante, mox supra columellam 

 sita ; infera obtusa, minus exstanti, columellari) instructa ; 

 peristomate recto, acuto, margine dextro omnino simplici, colu- 

 mellari reflexo dilatato. — Long. lin. 4^-vix 5 ; diam. rnaj. 

 circa 2. 



var. (3. subarmata. — Paries ventralis denticulo secundo 

 minuto tuberculiformi supra armatus. 



Auricula bicolor, Morel., Hist. Nat. cles Acor. 209. t. 5. f. 7 



(1860) 

 „ „ Drouet, Faun. Acor. 168 (1861) 



Alexia bicolor, Mouss., Faun. Mai. des Can. 136 (1872) 



Habitat Lanzarotam ; ad Salinas versus borealem insula?, 

 sub lapidibus in lutosis salsosis congregans. 



Tbe present shell, which was found abundantly by Mr. 

 Lowe and myself in muddy places at the edges of the Salinas, 

 or brine-pits, in the extreme north of Lanzarote, does not 

 seem to me to differ from an Auricula in my collection, taken 

 at Marseilles, which I have received as the A. myosotis, Drap., 

 and which indeed agrees sufficiently well both with the 

 diagnosis and the original figure of that species ; nevertheless 

 since it is possible that my examples from Marseilles may 

 be wrongly identified (for the A. myosotis is said by some 

 authors to be identical with the denticulata of Montagu), and 

 it is certain that the Canarian shell is conspecific with an 

 Azorean one which was enunciated by Morelet under the name of 

 A. bicolor, I think it safer perhaps to quote it under the latter 

 title in preference to that of myosotis. Nevertheless I think 

 there cannot be the remotest doubt concerning the identity of 

 the Lanzarotan species with that from Marseilles (whatsoever 

 the latter may be called), — the only points in which I can 

 detect the slightest shade of difference between the two consist- 

 ing in the fact that in the Canarian shell the upper (or first) 

 rudimentary tubercle on the ventral paries is more often absent 

 than present, and the aperture is perhaps just appreciably 

 narrower (or less outwardly enlarged) behind. 



The A. bicolor is a comparatively thin, Limncea-\ike 

 shell, a little shining and sub-pellucid, and with its pale horn- 

 coloured surface more or less darkly obscured (especially on 

 the spire) with a deep purplish tinge or bloom. Its spire is 



