148 



PROCEEDINGS OF THE ACADEMY OF 



[Feb., 



A NEW SPECIES OF MARINULA FROM NEAR THE HEAD OF THE GULF OF 



CALIFORNIA. 



BY HENRY A. PILSBRY. 



Marinula rhoadii n. sp. Fig. 1. 



The shell is imperforate, elliptical-ovate, rather solid; spire pale 



yellowish ; the last whorl has a dark band at the shoulder, and is pale 



yellow above, more or less suffused with 

 brown below the band. Surface smooth- 

 ish, under the lens showing fine, irregular 

 growth-lines (much more emphatic for a 

 short distance behind the outer lip) and 

 very faint excessively fine spiral striae. 

 Spire short, conic, attenuate near the 

 apex. Whorls 5f, slightly convex, the 

 last flattened or a little impressed below 

 the suture. Last whorl oval. Aperture 

 narrow, the outer lip thin, without callus 

 deposit within. Parietal lamella very 

 high and compressed. Two columellar 

 lamellae, the upper one larger. 



Length 10, diam. 5.8 mm.; length of 

 aperture 6.9 mm. 



Length 9 . 8 diam. 5 . 3 mm. ; length of 

 aperture 6 . 2 mm. 



Hardie River, Lower California, near Mt. Cocopah Major, types 

 No. 97,757 A. N. S. P., collected by Mr. S. N. Rhoads, Feb. 22, 1905. 



Compared with Marinula pepita King this species differs by its much 

 more inflated shape, the more slender spire, more or less attenuate 

 above, the nearly even suture, and the varied coloring. The face of 

 the columella is flat or concave in M. rhoadsi, and the parietal lamella 

 emerges further, approaching the edge of the parietal callus. In 

 M. pepita the face of the columella is convex and the parietal, lamella 

 does not emerge so far. 



This species is named for Mr. Samuel N. Rhoads, who made a 

 journey, not without difficulty and danger, down the Colorado River 

 below Yuma, returning along the bases of the arid mountains westward 

 to Calexico, California. 



Fig. 1. 



