GASTROCOPTA, SOUTH AMERICA. 97 



While Reibisch was probably correct in mentioning wolfii 

 as the species most nearly related to munita, the thick lip is 

 a feature recalling rupicola, marginalia and some forms of 

 barbadensis. 



Dr. W. H. Dall has discussed the tooth variations of this 

 species (loc. cit., p. 446), and has generously permitted me to 

 examine the material in the National Museum. As in several 

 other multidentate species of the genus, the infraparietal, 

 interpalatal and basal teeth, and the subcolmnellar callous, 

 are variable in development, and some or all of them may be 

 lacking in fully adult individuals. 



The original figure is copied in pi. 19, fig. 7. 



At Tagus Cove, Albemarle, which in the absence of definite 

 information may be taken as type locality, the shell varies in 

 color from a somewhat transparent cartridge-buff (pi. 19, figs. 

 1, 8) to cinnamon or tawny (fig. 3). Usually it is somewhat 

 opaque, and the periostracum is often worn. Under a strong 

 lens it appears minutely granulose, and is therefore not 

 glossy. The angulo-parietal lamella is more or less bifid in 

 front view, and seen from below the parietal projects slightly 

 on the columellar side (pi. 19, fig. 2). The infraparietal 

 tubercle is variable in size, as in other species having it. 

 Often it is a mere rudiment, and very rarely it is absent in 

 fully adult shells. The columellar lamella is stout, short and 

 horizontal ; often there is a buttress, sometimes somewhat 

 tubercular, under its inner end, as in rupicola, and some other 

 species; and as in these, it is individually variable, and not 

 due to age. The lower palatal plica is an entering lamina, as 

 in related species. The upper palatal is well developed, tuber- 

 cular. Basal plica smaller, tubercular or shortly entering. 

 There is a small interpalatal plica, variable in size and exact 

 position, and sometimes lacking. 



Length 2.65, diam. 1.3 mm. 



Length 2.45, diam. 1.1 mm. 



Length 2.45, diam. 1.2 mm. 



In another lot from Tagus Cove (Snodgrass) the extremes 

 of size are 2.15 and 2.45 mm. long. Others, found on crotons, 

 have no infraparietal lamella. Specimens found by Dr. G. 



