134 THE NAUTILUS. 



strigations: whorls seven, ventricose, moderately increasing above, 

 rapidly so toward the base, those of the spire carinated with a sloping 

 shoulder, lower whorls sub-carinate, flattened above and strongly 

 shouldered; lines of growth strong, decussated by numerous, closely 

 set, elevated, transverse lines; suture very deep; aperture rather 

 large, very oblique, regularly oval, sides nearly parallel, regularly 

 rounded above and below; outer lip thin, drawn back above and 

 somewhat sinuous ; inner lip closely appressed throughout. 



Alt. (Fig. 1 apex eroded) 30, width 18 mm. 

 u a 2 " 28 " 20 " 



This fine species, the largest yet known of the genus, was found in 

 some abundance in the Chipola River. Only a few occurred at the 

 other localities. 



It differs from all the described forms in its size and peculiar com- 

 bination of characters. Young specimens of about five whorls,, 

 except in being imperforate, slightly wider and more strongly 

 transversly striate, closely resemble striate specimens of X. sub' 

 carinata in shape, the shouldering and carination of the whorls 

 being almost exactly the same. But with increase of growth the 

 shape becomes entirely different and the mature shell in general ap- 

 pearance approaches Lea's L. elliottii, but differs from that species i» 

 being very much larger, proportionately wider, with the lower whorl 

 more flatly shouldered, with transverse raised lines and imperforate 

 axis. 



I take great pleasure in naming it after Dr. Pilsbry. 

 Goniobasis catenaria Say. Chipola River and Econfine Creek. 

 '• dooleyensis Lea. " " " 



This species is apparently one of the characteristic forms of the 

 Flint river drainage system. Originally described from Vienna in 

 Dooley County, Ga., the Messrs. King have found it in great abund- 

 ance in Rawle's Spring and Dry Creek, Early County, and in the 

 Chickasawahatchee Creek, Baker County. From Mr. A. C, 

 Billups, I have also received it from the Flint River. On the 

 present trip it was found in both the Chipola and Econfine. 



UNIONID^ FROM THE CHIPOLA RIVER. 



Medionidus kingii B. H. Wr. 

 Lampsilis paidus Lea. 



" subangulatus Lea. 



