62 UNIVERSITY OF COLORADO STUDIES 



Galba hendersoni Baker. 



Type locality, foothills west of Ft. Collins (Nautilus, Vol. XXII, p. 140). The types 

 were collected by L. C. Bragg, and further specimens by E. Bethel. 



Galba obrussa Say. 



Mud Lake at 8,000 feet, north of Allen's Park, Boulder County (S. A. Rohwer); 

 northeast of Ward at 8,500 feet, and Sulphur Springs (Dodds); Steamboat Springs, Box 

 Elder and two miles below Trapper's Lake (Henderson). 



Galba parva Lea. 



I found it fossil in the Pleistocene deposits of Denver, and one of the specimens was 

 identified and recorded by Dr. Baker. 



Galba palustris Miiller. 



Smartweed Lake near Rollinsville (Robbins) ; Sulphur Springs (Dodds) ; Saguache 

 (Cockerell); Grand River at Sulphur Springs, and Selah Lake at Granby (Bethel); Lake 

 George near Florissant, divide north of Rollinsville, grass-grown pond at Kremmling, 

 Muddy Creek above Kremmling, ditch at McCoy, an alkali lake in southwest corner of 

 North Park, cool water at margin of stream flowing from hot spring at Sulphur Springs, 

 on Curtis Creek northeast of Meeker and along White River from Meeker nearly to 

 Trapper's Lake (Henderson). This is the most generally distributed species of the genus 

 in Colorado, and is generally found in ponds, pools and lakes, rather than in streams. 



It is interesting to note that G. obrussa, cockerelli, hendersoni and caperala are often 

 found in ditches and shallow lagoons along the edge of the great plains, from which the 

 water is withdrawn during several months each year, the mollusks burrowing into the 

 mud and remaining dormant. 



G. sumassi should be eliminated from our fauna. Dr. Frank C. Baker writes, under 

 date November 23, 1908: "The Lymnaea sumassi is, as you suspected, only a form of 

 palustris, the true sumassi, types of which I have recently seen, being quite another 

 thing." 



Genus PLANORBIS Guettard 

 Planorbis trivolvis Say. 



Lake three miles west of Gold Hill at 8,500 feet (Miss Rosamond Patton); seven 

 miles northwest of Longmont (Spangler); Marvine Lodge in Rio Blanco County, and 

 Steamboat Springs (Henderson). This species seems to be much more common east of 

 the Continental Divide than west of it. 



Planorbis parvus Say. 



Pool two miles east of Ward at 8,580 feet, Tolland and La Junta (Dodds) ; six miles 

 below Trapper's Lake in Rio Blanco County, Fossil Ridge south of Ft. Collins, Buford 

 and Kremmling (Henderson). 



Planorbis exacuous Say. 



Lake between Gresham and Ward, at about 8,000 feet (S. A. Rohwer); Kremmling 

 (Henderson). The latter specimens are much larger than any I have seen from elsewhere 

 in Colorado. 



Planorbis antrosus Conrad. 



Vanatta (Nautilus, Vol. XXIV, pp. 136-138) has shown that the name P. bicarinalus 

 Say, commonly used for this species, was preoccupied, and Conrad's name is next in order. 



