SCIENTIFIC EXPEDITION TO NORTHEASTERN COLORADO 1 49 



work of earlier students. The careful student may expect to discover 

 much that is new to science. In gaining knowledge of his own state he 

 is extending the knowledge of the world. 



So far the University of Colorado has put forth but little effort along 

 this line. This little effort, however, has been fruitful in results and 

 promises great things for the future. We need expect nothing spectacu- 

 lar, but we may reasonably expect systematic and persistent effort to 

 be many times repaid. The results accomplished by the expedition to 

 which this account is devoted are simply an illustration of what may be 

 done with a very small expenditure of time and money. The several 

 accounts to follow give a fuller description of a part of the work done. 

 The notes and material of the expedition will be useful in the preparation 

 of more detailed papers to be issued later. 



2. Paleontology — Account of Collections Made 



By Junius Henderson 



The first paleontological work was done just outside the mouth of 

 Little Thompson canyon, northeast of Lyons, in Boulder County. There 

 a cache made several years ago was visited and the hidden collection 

 carried away. The collection consisted of some large fossil bivalves 

 (Inoceramus deformis) somewhat like clams of the present day. The 

 shells showed a well-marked constriction isolating the umbones from the 

 later accretions of the shell. This peculiarity gives the shell the appear- 

 ance of having completed its growth and then, as an afterthought, having 

 built a less strongly undulating extension.- This same condition some- 

 times occurs with /. oblongus at Fossil Ridge and with /, sagensis three 

 miles north of Boulder. It affords a striking example of variation 

 along parallel lines. 



Further east in the same valley, below the Hygiene sandstone in the 

 lower third of the Pierre group, a limestone concretion was found con- 

 taining numerous fossils. Prominent among these were a large number 

 of cephalopod fossils (Baculites compressus). There were also other 

 well-known Pierre fossils, including one undetermined bryozoan. So 

 far as known to the writer this is the only one, with a single exception, 

 thus far collected in this region. 



