Article XII. — Some Nczv Illinois Bnchyfrccidcc.* By Frank 

 Smith and Paul S. Welch. 



Nothing has been pubhshed on the BnchytrSdcc of the Mississippi 

 Valley with the exception of a brief description of Fridcricia agilis 

 by the senior author nearly twenty years ago ('95, p. 288) and the 

 insufficient account of the problematic forms from Lake Superior 

 by S. I. Smith and VerriU ('71). 



In this paper we first describe two new species of Fridericia from 

 Urbana, Illinois. The major part of these descriptions was con- 

 tained in a thesis offered by the junior author in 191 1 in partial ful- 

 filment of the requirements for the master's degree from the Uni- 

 versity of Illinois. We next extend the description of Fridcricia 

 agilis Smith and add a number of rather important characters not 

 previously given. Finally, we describe a new species of Marionina 

 from Urbana, Illinois, which is the first member of this genus re- 

 ported from the United States. Descriptions of seven other new 

 species of BncJiytrccidcc from the Mississippi Valley will soon appear 

 in a paper by the junior author which is about to go to press. 



The drawings for figures 22 to 28 inclusive were made by Mr. 

 S. Fred Prince, illustrator for the Illinois State Laboratory of 

 Natural History. All other drawings were made by the junior 

 author. 



FRIDERICIA Michaelsen 



About ninety species are assigned to this genus at the present 

 time, making it the largest genus of the family. Of this large as- 

 semblage of species only fourteen have been recorded from North 

 America, and only one from Illinois. Four species from the vicinity 

 of Philadelphia, Pennsylvania, one species from Havana, Illinois, and 

 seven species from California constitute the list for the United 

 States. So far as is known the members of this genus are all ter- 

 restrial in habit, although they usually occur under somewhat moist 

 conditions. 



The genus was established by Michaelsen in 1889, when he dis- 

 covered that certain species then assigned to Bnchytrccus, Neocnchy- 

 trccus, Mescnchytrccus and Archicncliytrccus had definite characters 

 in common which were of sufficient importance to justify the estab- 

 lishing of a new genus. Pie defines ('00, p. 106) the genus as fol- 

 lows : 



*Contributions from the Zoological Laboratory, University of Illinois, un- 

 der the direction of Henry B. Ward, No. 22. 



