THE NAUTILUS. 123 



A NEW VARIETY OF LIMNJEA. 



BY L. H. STRENG. 



Limnaea desidiosa viir. De Campi. 



Shell oblong, subconic, pale horn color, subdiaphanous, very finely 

 striated. Whorls about 5, rapidly enlarging, very convex and flat- 

 tened ; suture very deeply impressed, forming a considerable shoul- 

 der. Aperture about equal in length to the spire, not dilated, 

 elliptical; subumbilicate. Labium but a small portion appressed to 

 the body whorl, and the callus very light ; sinus of the fold not very 

 prominent. Length 5 mm., breadth 2-} mm. 

 Inhabits Brook's Lake, Newaygo Co., Mich. 



Remarks: The shell is rather slender in 

 appearance, its main features being the rapid 

 enlarging of the whorls and the shoulder. It 

 is most closely allied to L. doddioxa Say, ex- 

 cept in the prominent shoulder, and it is a great 

 deal smaller shell. It was discovered by Dr 

 De Camp several years ago, and has lain in our 

 collection ever since. I name it after my 

 friend Dr. DeCamp, who has done so much for the furtherance 

 of our knowledge of the Molluscan fauna of Michigan, especially 

 the western part of the State. 

 Nov. 22, 1895. 



DESCRIPTION OF A NEW GASTRODONTA. 



BY H. A. PILSBRY. 



Gastrodonta collisella n. sp. 



Shell rather solid, minutely perforate, above elevated and some- 

 what dome-shaped, below rather flattened, the periphery rounded. 

 Surface glossy, especially beneath, the base being radially finely 

 wrinkled, and with faint traces of spiral striation in the slightly ex- 

 cavated umbilical region ; upper surface sculptured with irregular, 

 arcuate wrinkle-riblets in the direction of growth-lines, and stronger 

 toward the sutures. Whorls 7-j, slightly convex, separated by very 

 shallow sutures, which, under the lens, seemed margined below by 

 the partial transparence of the shell. 



