OF NORTH AMERICA. ?>35 



Lymncea holbollii MOLLER, Ind. Moll. Groen., p. 5, 1842. REEVE, Voy. As- 

 sistance, p. 392, 1855. DALL, Moll. Alaska, p. 74, fig. 53, 1905. 



Limn&us holbollii KUSTER, Conch. Cab., p. 28, taf. 5, figs. 13, 14, 15, 1862. 



Limnophysa holbollii b. minor, BECK., p. Ill, 1838. 



Limnophysa holbollii, a major, BECK., p. Ill, 1838. 



Limnophysa holbollii TRYON, Amer. Journ. Conch., I, p. 254, 1865. 



SHELL: Small, elongate-ovate, conic, thin, more or less scalar; 

 color greenish horn ; surface dull to shining, lines of growth very fine, 

 crossed by microscopic impressed spiral lines ; whorls 5, well rounded, 

 not rapidly increasing in diameter; spire acutely conical, much longer 

 than the aperture; sutures well impressed; aperture roundly-ovate, in 

 some specimens almost continuous ; outer lip thin, no varical thickening 

 observed in the specimens examined; inner lip rather wide, triangular, 

 reflected over but not covering the umbilicus, which is rather widely 

 open; parietal callus thin; axis slightly twisted; varical bands on the 

 shell four or five in number. 



Length. Width. Aperture length. Width. 



14.00 7.00 mill. Vide Morch 



12.00 6.50 5.75 3.10 " Greenland 



11.50 6.00 5.75 3.25 " 



11.00 6.00 5.00 2.75' " 



TYPES: Museum of University of Copenhagen, Denmark. 



TYPE LOCALITY : Godthaab, Greenland. 



ANIMAL: "Dark yellowish-gray; tentacula narrower and more 

 pointed than L. vahlii" (Moller.) 



JAW, RADULA and GENITALIA : Unknown. 



RANGE : Greenlandian region. A typical boreal species, not known 

 to live outside of Greenland. 



RECORDS. 



GREENLAND: Greenland (Walker); Godthaab (Moller). 



GEOLOGICAL RANGE: Unknown. 



ECOLOGY: Found in a little tank in the mountains of Godthaab 

 (Motier). 



REMARKS : Holbollii may be known by its small size, long, acute 

 spire, short, roundly-ovate aperture and large umbilical chink. The 

 whorls are evenly rounded and the inner lip is quite expanded. It 

 differs from truncatula in its more regularly acutely-conic spire and 

 less compressed and more triangular inner lip. It greatly resembles 

 some specimens of caperata, but lacks the decided sculpture of that 

 species, besides having less rotund whorls and a differently shaped 

 inner lip. By most conchologists, holbollii has been ranged with vahlii 

 under Stagnicola, but its affinities seem rather to be with truncatula 

 under Galba. 



