NATURAL SCIENCES OF PHILADELPHIA. 125 



tibus cardinalibus parviusculis, compressis crenulatisque ; lateralibus sub- 

 longis lamellatisque ; margarita argentea et valde iridescente. 



Hab. — Rio Gigillillo, Corcuera, Nicaragua, Cen. Am., Mr. J. A. McNiel. 



GoNioBASis BAC0LOIDE3. — Testa Isevi, cylindracea, subtenui, luteola, qnadri- 

 vittata ; spira valde elevata ; suturis irregulariter impressis ; anfractibus plan- 

 ulatis ; apertura parva, rhomboidea, intus vittata et caeruleo-alba ; labro 

 acuto, vii sinuoso ; columella vix incrassata, contorta. 



Hab. — Coosa River, Alab., Dr. Schowalter. 



GoNiOBASis Lawrencii. — Testa leevi, subcylindracea, subcrassa, tenebroso- 

 cornea, dilute vittata vel evittata ; spira elevata ; suturis impressis ; anfrac- 

 tibus planulatis ; apertura par viuscula, rhomboidea, intus albida ; labro acuto, 

 sigmoideo ; columella incrassata et cortorta. 



Hab. — Washita River, near Hot Springs, Arkansas, Dr. Lawrence. 



ScHizosTOMA Lewisii. — Testa crebrissima striata, subcylindracea, subtenui, 

 luteo-fusca, imperforata ; spira conica, plicata ; suturis valde impressis ; an- 

 fractibus instar septenis, ultimo grandi ; fissura obliqua brevique ; apertura 

 grandi, rhomboidea, intus vittata ; labro crenulato, sinuoso ; columella alba, 

 incrassata et contorta. 



Hab. — Coosa River, Alab., Dr. Schowalter. 



Physa Carltonii. — Testa laevi, obtuse fusiformi, inflate, valde polita, tenui, 

 subpurpurea ; spira exserta, acuminata ; suturis impressis ; anfractibus senis, 

 ultimo pergrandi ; apertura ovata, grandi ; labro .expanse, intus marginato ; 

 columella impressa et contorta. 



^a6.— Mount Diablo, California, W. G. W. Harford. 



Phtsa Wolpiana. — Testa subrotunda, valde inflata, polita, tenui, tenebroso- 

 cornea ; spira valde obtusa ; suturis impressis ; anfractibus quaternis, ultimo 

 pergrandi; apertura ovata, grandi; labro expanso ; columella medio parum 

 impressa et parum contorta. 



Hab.— Eoi Springs, Colorado Ter., Prof. J. W. Powell. 



Notices of certain obscurely known species of American BIRDS. 



(Based on epeoimena in the Museum of the Smithsonian Institution). 

 BY ROBERT RIDQWAY. 

 Introdcctort Remarks. 



The following notes comprise the result of some examinations in the exten- 

 sive series of North American birds in the Museum of the Smithsonian Insti- 

 tution, to which I was kindly allowed access by Professor Henry. They were 

 made especially in connection with the determination of collections gathered 

 by myself as Zoologist to the U. S. Geological Survey of the 40th Parallel, 

 nnder Mr. Clarence King, principally in California, Nevada and Utah. 



Crossing so wide an extent of country as that indicated, it so happened that 

 the operations of the party allowed of extensive examination of the region 

 along the lines of junction of the three great " Provinces " of Professor Baird's 

 paper on the migration and distribution of North American birds, and I had 

 frequent occasion to confirm, and in some cases to extend his remarks rela- 

 tive to the affinities of the species of the different regions, and especially to 

 their hybridization, and to learn to what extent this may take place, and 

 therein tend to perplex the naturalist in his endeavors to determine the exact 

 character of his collections. When to this is added the change which con- 

 fessedly the same species undergoes under diflFerent climates, elevation, and 

 geographical distribution, it is no wonder that many cases exist in which 

 even our best critics may reasonably confess themselves at fault as to the pre- 

 cise name of the specimen, especially in view of the fact that many of them 



1869.] 



