36 AMERICAN JOURNAL 



Jun. L. Vahlii, Morch, Prod., No. 135. 

 L. Holbollii, Beck, Index, et Icones. 



Only a dozen specimens are known to me, all taken dead, 

 most of which were brought from Wormskiold in 1815. Mbller 

 found only a single specimen, with an attached Flustra, in dredg- 

 ing in a gulf at Arsut, not far from land. The accompanying 

 Greenlander believed he had seen it in a small lake some Danish 

 miles inland, from which a river runs out in the vicinity. A 

 collector has given me a specimen from Davis' Strait. Lucas 

 Barret took one or two with the dredge at Arsut. It resembles, 

 in the form of the columella and umbilicus, closely the following 

 species, but it is of a pellucid chalky-white color. 



8. Limn^ea (Limnophysa) Holbolii, Beck. Plate 4, fig. 8. 



T. conico-ovata, brunnea pellucida, striis incrementi rudibus, 

 lineis spiralibus aciculatis obsoletissimus ; fasciae incrementi 5 ; 

 anfr. subsenis convexis suturis impressis saepe albis ; spira longa 

 acutiuscula plerumque erosa ; apertura dimidio testa longitu- 

 dinis breviori orbiculari-ovalis ; lamina columellari lata reflexa 

 recta vix torta ; callus parietalis crassiusculus continuus ; rima 

 umbilicalis subinfundi fuliformis. 



Long. 14 mm. ; long. ap. 7 m. 



Animal dark yellowish-gray. Tentacula narrower and more 

 pointed than in L. Vahlii (Moller). 



Found in a little tank in the mountains of Godthaab (Moll.) 



This species is distinguished by its open umbilicus, small aper- 

 ture and long spire. 



L. Holbollii, Beck, Moll. Ind. 

 " Morch, Prod. 

 " Kuster, p. 28, t. 5, f. 13—15. 

 " Binney, 1. c, p. 59, f. 91. 



Moller s Descriptions of Lymnoea. Index, p. 4. 



L. Vahlii, Beck. T. ovato-oblonga ; spira convexa conica, 

 obtusiuscula; anfr. subsenis; sutura parum profunda ; apertura 

 dimidio testae longitudinis longiori. L. 9 /;/ . 



L. Holbollii, Beck. T. oblongo-ovata . spira conica, acutius- 

 cula ; anfr. subsenis ; sutura profundiori ; apertura dimidio testae 

 longitudinis breviori, rima umbilicali latiori. L. 6, 3' 



\U! 



