BIOLOGICAL PAPERS I43 



out adventitious roots as the trunk and branches are buried and 

 to produce adventitious shoots from the roots as they are exposed. 



4. The seedhngs apparently require a large amount of mois- 

 ture for their development, for they are found only along the 

 margins of ponds and streams, and in the pannes ; hence the 

 establishment of the cottonwood is antecedent to the dunes upon 

 which it is able to maintain itself. 



The University of Chicago. 



RECENT ADDITIOXS TO THE CAT-\LOG OF ILLIXOIS 



MOLLUSCA. 



Fr-axk Collins Baker. 



In 19061 the writer published a preliminary list of the Mol- 

 lusca known to live in Illinois. Since that time a number of species 

 new to the local fauna and new to science have been discovered. 

 These are briefly recorded in the following pages. There are 

 certain nomenclatorial changes, as well as other data, which can- 

 not be included in this paper, for lack of space. A revised catalog 

 will be in order as soon as time and opportunity is available. 



Page 76. — Margaritana margar tifera, Linne. This species 

 should be taken from the list. The record is based on specimens 

 mixed with monodonta, which is found in Illinois. 



Page 86. — For Conteocyclas^ peralata, read peralta. 



Page 86. — Add the following: Pisidiuvi neglectum, Sterki 

 Illinois (Sterki). Pisidium neglectum corpulentum, Sterki. Lily- 

 cash Creek, near Joliet, Will count}- (Ferriss; Handwerk). 



Page 89. — J'iz-ipara siibpurpurea texana, Tr}-on. This refer- 

 ence is to be omitted. The specimen did not come from Illinois. 



Page 93. — Amnicola limosa pallida, Hald, is a synonym of 

 limosa. 



Add the following: 



Page 93. — Amnicola sheldotii, Pilsbn.- ; incorrectly quoted on 

 page 95 as Pomatiopsis sheldotii. Amnicola missoitriensis, Pils- 

 bry. Canton, Fulton county (Walker). 



Page 99. — Physa ancillaria zcarreniana, Lea. Lake Forest, 

 Lake count}-. Lake Michigan (Woodruff). 



iBull. 111. State Lab.. X. H.. VII, Art. VI, Sept. 1906. 

 ^he name Pisidium is now generally acepted, and Corneocyclas cannot stand. 



