AZECA. 293 



there is a narrow callous ledge bordering the parietal callus, 

 extending to the base, and above rising into a triangular tooth 

 near the upper angle; a high median deeply entering parietal 

 lamella, the outer end of which, in well developed specimens, 

 curves downward and again inward, making a semicircular or 

 horseshoe-shaped callous ridge (see fig. 5). There is a small 

 supraparietal tubercle above the outer end of the parietal lamella. 

 The columella has an obtuse, deeply placed callous fold, and a 

 horizontal basal lamella. The outer lip is thick, its upper third 

 excised, and below the excision the margin is contracted; above 

 the middle it bears a prominent marginal tooth, with a more 

 deeply placed tubercle below it. Within the back of the last 

 whorl there are two tubercular plica?, the lower one larger. 

 Length 6.5, diam. 2.7 mm. 



Central Europe: Germany, France; type locality Pyrmont, 

 Germany. 



CarychiummenkeanumC. PFEIFFER, Systematisches Anordnung 

 u. Beschreib. Deutscher Land- und Siisswasser-Schnecken, p. 

 70, pi. 3, f. 42 (1821). Pupa menkeana C. PFR., Naturgeschichte 

 Deutscher Land- und Siisswasser-Mollusken, iii, p. 62 (1828). 

 Bulimus menkeanus MOQUIN-TANDON, Hist. Nat. Moll. terr. et 

 fluv. de France, p. 302, pi. 22, f. 7-14, with varr. nouletianus 

 and crystallinus. Azeca menkeana PJLSBRY, Journal of Con- 

 chology, xii, April, 1908, p. 137. Odontalus tridens Drap. , 

 PARREYSS, Syst. Verzeichniss, etc., p. 99 (1850). Achatina 

 goodalli ROSSMAESSLER, Iconographie, ii, p. 33, fig. 654. Azeca 

 tridens Pult. , PFEIFFER, Monographia Hel. Viv., ii, 276; iii, 522; 

 iv, 645; vi, 255; viii, 311 (see for full references); Conchyl. Cab., 

 Bulimus, p. 371, pi. 37, f. 27-30. 



Pulteney supposed that this species was the Turbo tridens of 

 Miiller, an error which various authors detected independently, 

 hence the multiplicity of names given it between 1821 and 1831. 

 As a specific name A. menkeana is preferable, since it was well 

 described and figured by C. Pfeiffer in 1821, while Ferussac's 

 name, goodalli, of the same date, was unaccompanied by de- 

 scription or figure, being based upon the accounts of Pulteney 

 and Montagu. 



