1913.] NATURAL SCIENCES OF PHILADELPHIA. 663 



transversely across the base, and slightly up the outer side, straight 

 and rather evenly arched; remaining palatal lamellae deep within 

 the shell, nearly horizontal, short, the lower one slightly larger. 



Greatest diam. 6, least diam. 5.25, alt. 2 mm. 



Two specimens of this species, which seems to be new, were taken 

 near the mouth of the main affluent of Papar^^ Lake with the species 

 noted above. 



It differs from S. janeirensis Clessin by the unusually deep descent 

 of the last whorl at the aperture. 



Genus GUNDLACHIA Pfeiffer. 



Gundlaohia bakeri Pilsbry, n. sp. 



Several specimens of this species were taken with Physa rivalis and 

 Planorbis anatinus in the artificial lake in Para. They were not 

 noticed at the time of collection, but were discovered in a bottle 

 of alcoholics containing the Physa rivalis and Planorbis anatinus 

 noted above. They are described by Dr. Pilsbry in a supplementary 

 paper. ^ 



SPH^IRIID^. 

 Genus EUPEKA Bourguignat. 

 Eupera. PI. XXVI, fig. 12. 



Shell rather small, delicate, very inequipartite, compressed, trans- 

 versely oblong, subrhomboidal, narrowing positively, and well 

 rounded anteriorly, the lower margin moderately curved, the pos- 

 terior broad and subtruncate, angulate above at the extremity of the 

 hinge line, subangulate below, sharply compressed posteriorly below 

 the hinge line, producing a sulcus extending from the umbo to the 

 posterior end of the valve at an angle of about thirty degrees from 

 the horizontal; everywhere sculptured with nearly even and evenly 

 spaced concentric costulse, about twelve to the millimeter on the 

 middle of the valve and considerably finer near the beaks; color a 

 slightly glistening yellow horn color, maculated irregularly and 

 rather closely with small purplish to black dots distributed in rather 

 radiating patterns and massing posteriorly to an irregular line along 

 the posterior sulcus. Beaks small, closely approaching, and pointing 

 forward, calyculate ; cartilage moderately exposed ; hinge line narrow, 

 straight posteriorly, very slightly curved anteriorly, armed with a 

 single, almo.st obsolete cardinal in each valve, two moderately 

 strong, simple laterals in the right valve and a simple anterior and a 

 strongly bifid posterior lateral in the left valve. 



Length 6, diam. 3, alt. 4 mm. 



