'90 PROCEEDINGS OF THE ACADEMY OF [DeC, 



A NEW HAWAIIAN LIMN^A. 



BY HENRY A. PJLSBRY. 



Limnaea hawaiensis n. sp. 



The shell is dextral, very narrowly rimate, oliliqviely ovate, thin and 

 light brown; sui-face very closely, finely and distinctly striate longi- 

 tudinally. The spire is extremely short and obtuse, 

 there being scarcely three whorls in all, se})arated by a 

 deeply impressed suture. The last whorl is convex below 

 the suture, then slopes outward, and is full and sack-like 

 at the periphery and base. The broad, ovate aperture 

 is oblique and nearly as long as the shell. The columel- 

 lar lip is reflexecl, and indistinctly folded alcove. 

 Length 6.5, diam. 5.3, length of aperture 5.5 mm. 

 Hawaii, in small streams in the moimtains on the Hilo side. Types 

 No. 85,380, A. N. S. P., collected by R. C. McGregor in 1900. 



The shell of this species approaches Erinna newconihi H. and A. Ad.,^ 

 described from Hanalei river, Kauai, in contour, but it is evidently 

 more closely related to Limncca affinis Souleyet.- That species was 

 described from streams on the island of Oahu, and is said to be "tou- 

 jours senestre," while every one of the 30 or 40 examples of L. hawaien- 

 sis taken is dextral. Although Pease claims that some of the Hawaiian 

 species are indifferently sinistral or dextral, it seems to me that the 

 alleged constant sinistral coiling of the Oahu form, and the equally in- 

 variable dextral convolution of this form from Hawaii, indicate that 

 the two islands are peopled by separate species of these short-spired 

 Limnaeas. 



Pease includes L. affinis Soul, and L. ^^ sandwichensis" Phil. {=sand- 

 wicensis Phil.) under L. oahuensis Soul, as synonyms.^ It is evident 

 that he had never seen Souleyet's L. affinis, or even the figures of it, 

 for it is as remote as possible from oahuensis. L. scmdicicensis Phil, is 

 a much more lengthened species than L. hawaiensis. 



None of the species described by Pease* and by CloukP are closely 

 related to L. affinis and L. hawaiensis. 



^ Genera of Recent Mollusca, II, p. 644. 



=* Voy. Bonite, Zool., II, p. ,528, PL 29, figs. 42-44. 



^ American Journal of Conchology, VI, p. 5. 



* Pease, t. c, pp. 5, 6. 



^ U. S. Exploring Expedition, Mollusca, Atlas, figs. 140, 1-12. 



