1 82 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



away. This species may be recognized by the two impressed lines on the 

 cast, and these casts are distinguishable at a glance from the casts of 

 Infnndibnlnni corrugatum which are found associated with them by the 

 much shorter diaphragm, which does not form a complete revolution, but 

 only part of it. 



The generic name Galerus Humphreys, 1797, takes precedence over 

 Calyptrcea Lamarck, 1799 (see Tryon, 1886, p. 103), and this genus is 

 distinguished from Infundibulum chiefly in the columellar margin of the 

 diaphragm, which is reflected, and forms a false umbilicus. 



Record of specimens : Shell Gap, Rio Chico, upper horizon, i cast; 

 Lake Pueyrredon, 600' above base, 14 casts. 



Distribution: Lebu and Guayacan, Chili (Phil.). 



113. GALERUS MAMILLARIS (Broderip). 



PI. XXXII, Fig. S"'". 



1859 Trochita m. Reeve, Conch. Icon., v. 11, p. 3, f. 12. 

 1886 Calyptrcea m. Tryon, Man. Conch., v. 8, p. 120. 

 1897 Cal. aff. mam. Pilsbry, in: Pr. Acad. Philad., p. 330. 



Shell subcircular, conical, elevated or depressed. Apex central. Sur- 

 face with concentric lines of growth, otherwise smooth. Interior with a 

 spiral diaphragm, making i to 2 complete revolutions, the columellar 

 margin is reflected, and forms a distinct false umbilicus. 



Height, 1 6 mm, diameter, 20 mm; height, 10 mm, diameter, 18 mm; 

 height, 9 mm, diameter, 24 mm. 



Remarks: There is some variability as to the external form: the shell 

 is more or less high, as shown by the measurements given above. 



We possess only inner and outer casts, and, superficially, the internal 

 casts very much resemble Infundibulum corrugatmn. But the radial ribs 

 of the latter are completely absent, as is shown by a number of external 

 casts, and a closer examination reveals the fact that the columellar margin 

 of the diaphragm was reflected, forming an umbilicus. This umbilicus is 

 filled with matrix in the cast, and, after breaking away the upper whorls, 

 the cast of the umbilicus is well exhibited in a number of specimens (see 

 plate XXXII, fig. 8*). 



This species differs from G. araucanus at once in the number of revo- 

 lutions of the diaphragm : while in G. araucanus the diaphragm does not 



