68 DR. W. BAIRD ON NEW SPECIES OF SHELLS FROM [Feb. lOj 



while the aperture is of considerable length, and the columella at the 

 base suddenly arched. 



6. SucciNEA HAWKiNsii, Baird. 



^.testa elongato-obovata, tenui,pellucida, nitida, undulato-striata, 

 rubella, intus margaritacea, spira acuta ; anfractihus quatuor, 

 convexis, ultimo duos trientes longitudinis testce adequante, 

 sutura impresna, apertura ovali, inferne effusa. 

 Long, f inch ; lat. J inch. 



Hah. Lake Osoyoos, British Columbia. {Mus. Brit.) 

 This shell is of an elegant form, and of a pinkish colour, with the 

 interior of a pearly lustre. It is smooth and shining, but marked 

 with waved striae of lines of growth. It resembles very much in 

 figure the Succinea pfeifferi of Europe, but is of a still mere elegant 

 shape, and of a brighter hue. 



I have named it after Lieut.-Col. Hawkins, R.E., Commissioner 

 of the British North-American Boundary Commission. 



7. LiMN^A suMASSii, Baird. 



L. testa elongata, attenuata, cornea, fragili; anfractihus sex, 

 ultimo cceteris duplo majore ; apertura mediocri ; columella 

 forte plicata ; superficie externa, suh lente, creberrime et minu- 

 tissime decussata. 

 Long., largest, 1^ inch ; lat. 1 inch. 



Hah. Sumass Prairie, Fraser River, British Columbia. {Mus. Brit.) 

 This species of Limneea approaches L. elodes of Say, but is more 

 elongated, more fragile, and has the columella very strongly plicated. 

 The surface of the shell, when seen under a lens of moderate power, 

 is finely decussately striated. It is of a horny colour, and is of an 

 elongated shape. 



8. Physa lordi, Baird. 



Ph. testa tenui, majuscula, cornea, tumida, gibhosa, apertura 

 magna ; lahro acuta, linea alba seiifusca externe notato; super- 

 ficie externa minutissime decussata; anfractihus sex, duohus 

 primis minutis, nigro tinctis, ultimo tumido, cceteris quadruplo 

 majore. 

 Long, from f to 1 inch ; lat. from v to f inch. 

 Hah. Lake Osoyoos, British Columbia. {Mus. Brit.) 

 This species is one of the largest of the genus, and is much swollen 

 and gibbous. The outer lip is generally marked with a streak of 

 brown edged with white, which mark is left in those specimens which 

 are of older growth, leaving a white callous-looking line of growth 

 edged with brown, nearly in the centre of the last whirl, which is very 

 large, being about four times the size of all the others put together. 

 The two upper whirls, which are very small, are of a black colour. 

 The surface of the shell is finely decussately striated. 



The Physa heterostropha of Say abounds in the Sumass Prairie, 

 on the Fraser River ; but its place seems to be taken on the higher 

 ground towards the Rocky Mountains by the Ph. lordi. 



