ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 283 



94. Columbella labiosa. Rare S. P. 



95. Anachis rugosa. 1 sp S. P. 



96. Anachis fulv a. 1 sp P. M. 



97. Pisania ring ens. Rare P.M. 



98. Mur ex radix. Rare P. 



99. Mur ex regius. Common P. M. 



88. Purpura patula. Rare M. 



89. Purpura biserialis. 1 sp....S. P.M. 



90. Purpura triserialis. 1 sp M. 



91. Purpura melones. Rare S. P. 



92. Monocerosbrevidentatum,Grsiy. 1 sp. 



S. P. 



93. Columbella fuscata. Rare...S. P. M. 



This collection, containing 99 species, of which only one is certainly and 

 another perhaps imported, shows what a common sailor may do, simply by 

 keeping his shells from being mixed. One species is new; 46 are common 

 to both Mazatlan and Panama ; 29 are found at Panama, but not at Mazatlan ; 

 6, though not yet quoted from Panama, are southern types; 14 are found at 

 Mazatlan, and not at Panama ; 6 are northern types, being found in Lower 

 California, and of these, two (viz. Acmcea grandis and Pomaulax undosus 

 [operc.]) were not found at Mazatlan. 



57. In the Proceedings of the Boston Soc. Nat. Hist, for Feb. 1855, Dr. 

 A. A. Gould described the following land and freshwater shells from the 

 western part of N. America : — 



P. 127. Helix ceruginosa, Gld. San 



Francisco, Dr. Bigelow. 

 P. 127. Helix infirmata, Gld. San Fran- 

 cisco, Dr. Bigelow. 

 P. 128. Physa bullata, Gld. Oregon, 



Dr. J. G. Cooper. 

 P. 128. Physa humerosa, Gld. Colorado 



Desert, Dr. Th.H. Webb; Pecos River, 



Mr. W. P. Blake. 

 P. 128. Physa virgata, Gld. River 



Gila and near San Diego, Dr. Th. H. 



Webb. 



P. 129. Planorbis amnion, Gld. Colo- 

 rado Low Desert, Dr. T. H. Webb, 

 Mr. W. P. Blake. 



P. 129. Planorbis gracilentus, Gld. 

 Great Colorado Desert, low lands, 

 Dr. T. H. Webb. 



P. 129. Amnicola protea, Gld. Colorado 

 Desert, Dr. T. H. Webb, Mr. W. P. 

 Blake. = Melania exigua, Conr. (read 

 Feb. 13th). 



P. 130. Amnicola longinqua, Gld. Co- 

 lorado Desert, Mr. W. P. Blake. 



The same gentlemen appear to have made collections on the coast; of 

 which the following lists have been obligingly sent by Dr. Gould. 



Collected by Dr. Thomas H. Webb. 



At Guaymas. 

 Acmcea ceruginosa [=A. mesoleuca,var.]. 

 Neritina picta. 

 Nerita " ? prcecognita, C. B. Ad."= 



Bernhardi, Reel. 

 Chlorostoma rugosum, var. 



At San Diego. 

 Tellina nasuta. 

 Donax. 

 Venus dispar. 

 Venus, sp. 



Cardium Calif or niense. 

 Area pernoides. 1 valve. " Lieut.Webb." 

 Pectunculus (dead, rubbed). 

 Pecten (dead valve). 



Ostrea. 



Fissurella crenulata (very young). 



Haliotis ? Kamtschatkana. 



Trochus viridulus (very red var.). " Lieut. 



Webb." 

 Phasianella compta 

 Calyptrcea hispida,=Cruc. spinosum. 

 Cerithium irroratum, Gld. 

 Potamis pullatus, Gld. 

 Cerithidea albonodosa. 

 Natica tuber. 

 Ranella muriciformis. 

 Oliva splendidula. 

 Nassa luteostoma. 

 Nassa tegula, Rve., dead. 

 Purpura emarginata. 



It is probable that some of the above shells, as Ranella muriciformis, Oliva 

 splendidula, Nassa luteostoma, Natica uber, had found their way northwards 

 by the accidents of commerce. None of them were seen by Mr. Nuttall, who 

 spent some time at the place. 



