THE NAUTILUS. 123 
A NEW VARIETY OF LIMNZEA. 
BY L. H. STRENG. 
Limnea desidiosa var. De Campi. 
Shell oblong, subconiec, 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. desidiosa 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 73, slightly convex, separated by very 
shallow sutures, which, under the lens, seemed margined below by 
the partial transparence of the shell. 
