654 PROCEEDINGS OF THE ACADEMY OF [DeC, 



showing a tendency to become tuberculate. Apex eroded in all 

 specimens, about 4 whorls of the type remaining intact, the varia- 

 bility of the immature specimens making it impossible to estimate 

 how many are lacking. Aperture oblique, of an evenly distorted 

 pear shape, light colored within except where the epidermis extends 

 over the lower portion of the parietal wall for about half a turn, 

 separating the dirty white callus on the upper portion, with its indis- 

 tinct posterior canal, from the yellowish nacre of the concave, slightly 

 revolute columella; outer lip sharp, crenulated by the external 

 sculpture; basal lip effuse at a point rather distant from the base 

 of the columella. 



Alt. 44.5, diam. 17, length of aperture 13 mm. 



Eleven specimens were taken, presumably with the last species, 

 in the Rio Iriri. 



This species is related to D. rixosa Ihering by the smooth initial 

 whorls, tending to show spiral sculpture, but it differs in the develop- 

 ment of strong, tuberculate, vertical ribs on the last whorl and in 

 the oblique, concave, revolute columella. It is named for Dr. 

 Harold Heath, of Stanford University, a member of the Expedition. 



There is a curious relationship shown by the members of the group 

 including D. rixosa and the last three species, passing from the 

 elongate D. rixosa with only spiral sculpture, showing mostly on the 

 last whorl, through the elongate D. heathi with a similar spire, but 

 having on the last whorl strong vertical ribs and spiral keels with a 

 subangulation Ijy the two rows of tubercles, and through the stouter 

 D. starksi with a very similar sculpturing of the last whorl, but with 

 the earlier whorls ranging from rather smooth to heavily sculptured 

 and tuberculate, to the globose D. globosa with its almost regular 

 costate and tuberculate sculpture throughout. In all, unless it be 

 D. rixosa, which I have had no opportunity of examining, the keels 

 are in series of fives, and in the last two there is a marked tendency 

 to the elongation of the tubercles along spiral lines. All are very 

 distinct species, but it is not improbable that two or more of them 

 may ultimately have to be united with varietal rank when the field 

 shall have been fully explored and full suites of all the species secured. 

 Doryssa iheringi n. sp. Pi. XXV, fig. 8. 



Shell turreted conic, solid, tapering regularly; epidermis rather 

 heav}^, slightly shining, light chestnut to very dark brown, the 

 lighter specimens marked by small, irregular, and irregularly placed 

 black spots; initial whorls lost in all specimens, remaining whorls 

 rather flat, showing obsolete vertical ribs at the top which fade into 



