30 THE NAUTILUS. 



CYCLADIDJE OF THE SOUTHEKN STATES. 



BY V. STERKI. 



The year 1904 has brought us many good things in the line of 

 Cycladidas, especially from the South, from Indiana and from Can- 

 ada. Our knowledge of these small bivalves from the Gulf States 

 has been very limited. Mr. H. E. Sargent had done some collect- 

 ing in North Alabama, and Mr. Frierson in North Louisiana, and 

 a few lots had been seen from other states. The collecting of Mr. 

 Smith in Georgia and Alabama, mainly along the Coosa river, and 

 of Mr. A. A. Hinkley in Alabama and Mississippi, have opened that 

 territory known as particularly rich in Strepornatidse and Unionida?, 

 and added considerably in regard to systematics as well as geograph- 

 ical distribution. The specimens collected by Mr. Smith were 

 kindly sent for examination by Mr. Bryant Walker, those of Mr. 

 Hinkley partly by himself and partly by Mr. Walker. The follow- 

 ing list and notes may be of interest to students of a much neglected 

 yet integral part of our mollusk fauna : 



Pisidium virginicum Gm. From Georgia, Alabama and Missis- 

 sippi, common and rather variable. The prevalent form along the 

 Coosa river is decidedly oblique and rather angular in outlines; it 

 may represent a variety. 



Pis. compressum Pr. Common and decidedly variable, making a 

 considerable addition to the already wide range of variation of this 

 species, and some forms seem to represent real varieties. 



Pis. kirklandi Sterki. Shoal creek near Florence, Town creek at 

 Monte vallo, Ala., full grown and young specimens ; seen from the 

 South for the first time. There is a small but distinct roundish, 

 somewhat raised, granular area in the center of each beak, a char- 

 acteristic feature of the species, not noted in the description (THE 

 NAUTILUS, xiii, p. 11, 1899). 



Pis. cruciatum Sterki. Shoal creek, Florence, Ala., collected by 

 Mr. Hinkley. This minute Pisidium, distinguished by the unique 

 formation of its hinge and the shape of the ridges on the beaks, had 

 also been known only from Ohio, Michigan and Illinois (also fossil). 



Pis. fallax Sterki. Two badly eroded specimens from the Town 

 creek, Monte vallo, Ala. The species is widely distributed and vari- 

 able, and specimens of it are generally more eroded than any others. 



