226 FERUSSACIA. 



PFR. Monogr. vi, 249. GODWIN- AUSTEN, P. Z. S. 1880, p. 

 662, pi. 64 (anatomy). NEVILL, P. Z. S. 1880, p. 133, pi. 14, 

 f. 2; with var. subamblya, p. 133, var. subfolliculus, p. 134, 

 and var. subforbesi, p. 134. Vediantius eristalius Risso, Hist. 

 Nat. Eur. Merid. iv, p. 82 (young specimen). Cionella g., 

 WESTERLUND, Fauna, p. 155. 



This species is especially distinguished by having the pen- 

 ultimate whorl much swollen on the left side. F. vescoi is 

 certainly closely related, but the columellar fold is stronger, 

 at least typically. Bourguignat redescribed and figured the 

 species from Risso 's type specimen. 



Var. subamblya Nevill. 



"This is a short convex form, with the last whorl a good 

 deal more rounded, the aperture less everted, with the colu- 

 mella straight. They increase very slowly and regularly, the 

 difference of the antepenultimate one in this respect, from 

 that of the typical form, being very marked. It may prove 

 a distinct species; but I am inclined to doubt it at present. 

 I only found a few specimens living with typical form." 



"Long. 814, alt. 31/3 millim." (Nevill). 



Men ton (Nevill). 



Var. subfolliculus Nevill. 



"? Ferussacia folliculus Gronovius (as figured by Bourg. 

 Mai. Chateau d'If. pi. ii. fig. 2, long. 9, diam. 3 millim.). A 

 few specimens only met with living with typical F. grono- 

 viana; they agree well with the above-quoted figure. The 

 body whorl is more elongately and evenly rounded, not tumid 

 towards the base, and appears longer in proportion than in 

 the typical form." (Nev.) 



"Long. 9, diam. 3% millim.; apert. alt. 3% millim. (Nev.) 



Men ton (Nevill). 



Var. subforbesi Nevill. 



"? Ferussacia forbesi, Bourg. Mai. Alg. (long 8y 2 , diam. 

 4 millim., Algiers). I doubt this variety, in especial, being 

 specifically distinct. The whorls of the spire are only slightly 

 irregular; the last whorl more convex, columella straighter. 



