348 PROCEEDINGS OF THE ACADEMY OF [April, 



low callus upon the columellar wall above. The anterior notch is 

 rather wide and shallow. 



Length 9.0, diam. 4.2 mm. (type). 

 " 8.6, " 4.1 " 



Chiefly notable for its narrow shape and the long, emerging colu- 

 mellar folds. Named for the Rev. Leander T. Chamberlain. 



Marginella coniformis Sowb. PI. XXIV, fig. 12. 



Marginella coniformis Sowb., Journ. Geol. Soc. Lond., VI, p. 45 (Santo 

 Domingo). 



The specimens agree very closely with the small Bowden race of 

 this species, which has been very poorly figured by Guppy (Q. J. Geol. 

 Soc, XXII, PL 17, fig. 2); but the Gatun shells are even smaller. 

 Specimens measure: 



Length 15 . 8, diam. 9 . 7 mm. 

 " 14.3, " 9.1 " 



M. ballista Dall is broader at the shoulder, but otherwise related. 



OLIVIDiE. 



Oliva reticularis gatunensis Toula. 



Oliva gatunensis Toula, Jahrb., p. 702, PL 25, fig. 12. 



Cf. Oliva liodes Dall, Trans. Wagner Inst. Sci., PI. 58, fig. 1. 



This abundant form is not really distinguishable from the living 

 0. reticularis, except by its smaller size, length 35 to 38 mm. 



FASCIOLARIID^J. 



♦Glyptostyla panamensis Dall. 



Glyptostyla panamensis Dall., Trans. Wagner Inst. Sci., Ill, p. 233, PL 13, 

 fig. 5. 



Not seen by us. Vamos-vamos Station, 19 kilom. from Colon. 

 The genus Glyptostyla is also known from the Martinez Eocene of 

 California, but the species of that bed, G. crassitesta (Gabb), is very 

 unlike the Isthmian form in sculpture, and cannot be considered 

 nearly related. 

 Fasciolaria sp. undet. 



Internal casts of a species not unlike the Chipolan F. ramondi Maury 

 were taken at Gatun. 



BUOOINID^J. 

 Solenosteira dalli n. sp. PI. XXIV, fig. 14. 



The shell is biconic, solid and thick. Spire conic, acuminate when 

 perfect, with about 2\ smooth embryonic whorls, the following whorls 

 very convex, with sculpture of massive longitudinal folds not quite 

 as wide as the intervals, and sharp spiral cords and threads passing 



