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PROCEEDINGS OF THE NATIONAL MUSEUM 



occupying middle ventral area within inner margin of inner lamella 

 (fig. 4(/). 



The carapace of S. americana illustrated by Cushman (1906, pi. 27: 

 fig. 1) is labeled: "Shell of female seen from the side." This illus- 

 tration shows the left valve. It has been interpreted as the right 

 valve by Poulsen (1965), who, in his "Key to the Species of the Genus 

 Eusarsiella," distinguishes americana from zostericola by the former 

 having a few irregular teeth along the anteroventral margin of the shell. 



'^^^^y^-r-frrn^rrmrr^i'^ 



Figure 3. — Sarsiella zostericola Cushman, Hadley Harbor, Mass., adult 9, sta. P. 1907, 

 1.25 mm: a, left lateral view; b, dorsal view, anterior to left. Adult cf, sta. P. 264.25, 

 1.01 mm: c, left lateral view; d, dorsal view, anterior to left. 



The "teeth" described as spines by Cushman (1906, p. 363) are 

 actually along the posterodorsal margin. The illustration of Cushman 

 (pi. 27: fig. 1) does, in fact, look more like a right than left valve 

 because the valve is higher than it is long. This indicates that the 

 drawing is of a distorted valve because Cushman (1906, p. 363) states 

 that the length of the shell is very slightly greater than the height. 

 Mean lengths of selected adult females from San Francisco, CaHf., 

 Hadley Harbor, Mass., and Port Isabel, Tex., are 1.23 mm (N = 17), 

 1.24 mm (N=8) and 1.28 (N = ll), respectively. These means do not 



