104 THE NAUTILUS. 



Except the Anodonta these species have not yet been recorded 

 anywhere else in Colorado, though we have in the University of 

 Colorado Museum unreported specimens of the Anodontoides 

 from Julesburg, Denver and Boulder. Possibly Lampsilis no 

 longer lives in the State. In 1912, in company with Dr. Max 

 M. Ellis, I visited Lodgepole Creek and searched the stream 

 from the northern state boundary to its junction with South 

 Platte River. We found no Unionidae except some dead shells 

 of Anodontoides. Perhaps that species was still living in a deep 

 pool a few rods south of the state boundary, though in seining 

 it for fishes we found none. A rancher near by told us there 

 were " clams " in the pool. The rest of the stream was shallow 

 and so narrow one could step or jump over it in most places. 

 Probably later in the summer of dry, hot seasons, when the 

 natural flow was diminished and the demand for irrigation 

 water is great, it may entirely dry up in its lower course. 1 

 wrote to Mr. Simpson, calling his attention to present condi- 

 tions and the evident disappearance of the Lampsilis, and ask- 

 ing what the conditions were when he was there. He replied 

 that as he recalled it the creek was then from 6 to 10 feet wide, 

 but that the taking of water from the South Platte for irrigation 

 had caused the river to go dry at Julesburg during his three 

 years residence, and suggesting that the same thing had likely 

 since happened in the creek. This seems exceedingly probable. 

 Mr. Simpson also added: "The Unio anodontoides is probably 

 Lampsilis falladosus, not then recognized." My intention in 

 1912 was to publish an account of our experience, but it was 

 side-tracked and finally passed out of mind. It has recently 

 been brought forward by finding in the report of the Fremont 

 Expedition, 1845, p. 25, the statement that on July 6, 1842, 

 Lodgepole Creek was a "clear, handsome stream" (hence at 

 low water stage), with a "uniform breadth of twentj^-two feet 

 and six inches in depth." This confirms the supposed dimin- 

 ution of water in the stream in recent times. 



In 1906 the bed of the lower portion of Crow Creek, east and 

 northeast of Greeley, Colorado, was dry, except just after storms, 

 the water percolating through the deep sand in the channel, a 

 characteristic of many western streams. Up stream, just above 



