THE WEST AMERICAN MOLLUSKS OF THE GENUS 



EUMETA. 



By Paul Bartsch, 



Assistant Curator, Division of Mollushs, U. S. National Museum. 



Three species only of the genus Eumeta are known from the west 

 coast of America. They are all southern. E. intercalaris Carpenter 

 comes from the Mazatlanic area; E. himarginata C. B. Adams has 

 been seen from the Gulf of California and Panama; while the third, 

 E. eucosmia Bartsch, comes from the Galapagos Islands. '^ 



The drawings accompanying this paper were made by Miss Evelyn 

 G. Mitchell. 



EUMETA INTERCALARIS Carpenter, 



Cerithiopsis intercalaris Carpenter Proc. Zool. Soc. London, 1865, p. 281. 



Shell regularly conic, wax-yellow, with the posterior line of tuber- 

 cles on each whorl light brown. (Nuclear whorls decollated.) Post- 

 nuclear whorls concave in the middle, marked by a double spiral 

 series of tubercles. The posterior of these two rows is a little below 

 the summit, leaving a very narrow, plain cord at the summit; the 

 anterior row being immediately above the suture. These tubercles 

 are joined spirally and axially by slender riblets, which inclose well- 

 impressed, squarish pits. On the last two turns a third slender 

 spiral cord occurs between the other two, a little nearer to the posterior 



« In the preparation of the present diagnoses the following terminology is used: 

 "Axial sculpture," the markings which extend from the summit of the whorls to- 

 ward the umbilicus. 

 The axial sculpture may be — 



"Vertical," when the markings are in general parallelism with the axis of the shell. 

 "Protractive," when the markings slant forward from the preceding suture. 

 "Retractive," when the markings slant backward from the suture. 

 "Spiral sculpture," the markings following the directions of the coils of the whorls. 



Proceedings U. S. National Museum, Vol. 39— No. 1799. 



565 



