Occasional Papers of the Museum of Zoology 65 



in shape; internally light to dark chocolate, when light it 

 shows darker, spiral bands; peristomal callus white. Peri- 

 stome: palatal and basal walls rather narrowly but quite 

 abruptly expanded; columellar region more extensively ex- 

 panded (although less so than in megacheilos) ; parietal angle 

 produced; palatal emargination very slight (fig. xiii-K) ; in- 

 ternal callus extensive but very thin, practically absent on 

 parietal wall. 



Operculum : Si/o whorls ; similar to megacheilos, but nuclear 

 erosion more extensive, calcareous portion slightly smaller than 

 chondroid plate, and entire outer surface (calcareous plate) 

 distinctly concave, although much less so than in T. pilshryi. 



Radula : similar to megacheilos. 



Measurements 



Shell Aperture Operculum Whorls 



alt. maj.diam. min.diam. alt. diam. long wide 

 male 



(type) 13.0 58(7.5) 48(6.2) 45(5.9) 93(5.5) 37(4.8) 79(3.8) 6(eii- 



tire) 



female 15.0 61(9.2) 49(7.3) 48(7.2) 93(6.7) 35(5.3) 76(4.0) 4 



Cbl7b. Frequent (195 specimens collected). Typical lot (see Table 

 VII) ; coloration very uniform. 



Cbl7a. Apparently infrequent, but the abundance of this sub-species 

 can only be judged during rain-storms (13 specimens). Tj'pical fossor. 



Cbl6. Very rare; 1 dead, bleached specimen. 



Cb20. Apparently quite rare (3 specimens). Typical fossor reaches 

 an altitude of around 1,200 feet on Sint Christoffelberg. 



C20. Frequent (70 specimens). Slightly larger, with lighter ground- 

 color, and much more variegated color; a quite divergent form. 



Tudora fossor djerimensis, new subspecies 



Type locality: (ClTb) top of shore cliffs between Knip Baai 

 and Plaja Djerimi, northern Curasao. 



Distribution: Curasao; western limestone rim from both 

 sides of Plaja Abau to Salinja Sint Marie (C13, 14, 15, 16, 

 17) ; also one, dead, bleached specimen from Seroe Spreit 

 (C8). Quite infrequent to very rare; under limestone rocks; 

 almost completely terrestrial. 207 specimens collected. 



