20 THE NAUTILUS. 



new subgenus, EOSINICA, which may be described as ovate-conic, 

 radially ridged, interior smooth, terminating in a rounded protuber- 

 ance and interior margin generally crenulated. 



GASTROCH.ENA STRIATULA n. sp. Fig. 2. 



Shell small, substance thin, ventral opening large, ovate anteriorly 

 and pointed at posterior with its margin turned outward towards the 

 anterior end of shell. The shell is pointed anteriorly, rounded pos- 

 teriorly with surface closely concentrically striated. Widest part of 

 valve 6 mm., length 10 mm. 



Locality. Wood's Bluff, Ala. This specimen was found im- 

 bedded in a coral, and unfortunately was broken. The cavity is 

 rounded and smooth. It is rather wider and shorter than usual in 

 this genus. 



Part of type in my collection, balance in State Museum. 



NEW PISIDIA. 



BY V. STERKI. 



Pisidium ohioense n. sp. 



Mussel minute, equipartite, well inflated, elliptical in outline ; 

 beaks in the middle, rather broad, rounded, prominent over the 

 hinge line ; superior margin little curved or almost straight, with 

 slightly marked, rounded angles at the scutum and scutellum ; the 

 other margins rounded or the posterior subtruncate ; surface some- 

 what shining, horn colored, very finely and irregularly striate, 

 usually with a few coarser lines of growth ; shell thin, translucent ; 

 nacre glassy-transparent, muscle insertions slightly marked ; hinge 

 fine, plate narrow, cardinal teeth fine, lamellar, the right slightly 

 curved, abruptly thickened and bifid at the posterior end, the left 

 anterior longitudinal, almost straight, the posterior slightly oblique 

 or longitudinal and parallel with the anterior and extending to over 

 about its middle ; lateral teeth comparatively stout, their cusps 

 pointed, the outer ones of the right valve small but well formed ; 

 ligament rather stout. 



Size : Long 2.5, alt. 2-2.1, diam. 1.5 mill. 



Long 2, alt. 1.6-1.7, diam. 1.2-1.4 mill. 



Long 1.8, alt. 1.5, diam. 1.3. 



Young: Long 1, alt. 0.8, diam. 0.3 mill. 



