530 The Ohio Naturalist. [Vol. VI, No. 7, 



Thorax, .31 mm. long, .47 mm. wide; greatly constricted at middle. 

 Prothorax twice as broad as long, much narrower than head; anterior 

 angle rounded, two small hairs with bristle between, two :nore bristles 

 near posterior angle, several small bristles along posterior border; a nar- 

 row transverse band one-third of the way from front, with longitudinal 

 bands near each end, diverging bands running half-way to front from 

 posterior border. Metathorax shorter and broader than prothorax with 

 straight diverging sides, also nearly straight anterior and posterior su- 

 tures; two long bristles at posterior angle, twelve long hairs along posterior 

 border; a little darker than prothorax. Legs rather large especially the 

 femur, and fulvous. 



Abdomen with sides and posterior evenly rounded, wide transverse 

 bands extending from side to side, sutures curved except last one; invag- 

 inations in the chitin of the lateral margins of all the seg:nents except 

 the last two produce clear notch-like spaces; one large and one small bristle 

 at posterior angles of all but terminal segment; numerous long hairs on 

 posterior borders of segments ; fringe of fine hairs along sub-margin of last 

 segment; last three sutures marked by clear spaces; first four segments 

 have three small hairs on lateral margins. 



Described from specimen in Professor Osbom's collection, 

 taken from Aegialitis vocifera at Ft. Collins, Colo., by R. C. 

 Stephenson. 



This work was carried on in the Zoological Laboratory of 

 Ohio State University under the direction of Professor Herbert 

 Osbom, to whom the writer wishes to express his thanks for val- 

 xiable assistance. 



KEY TO THE SPECIES OF LIVERWORTS RECOGNIZED 

 IN THE SIXTH EDITION OF GRAY'S MANUAL OF 



BOTANY. 



Edo Claassen. 



This key may be considered as a continuation of the one pub- 

 lished last year in the Ohio Naturalist (Vol. V, p. 312.) Its pur- 

 pose is therefore the same; it is intended to make the study of 

 the liverworts and their determination more easy. It was 

 thought to be necessary to put into the key more characters than 

 are usually given. Rather than hamper the student in any way 

 in his efforts to determine the liverworts, this extended key is 

 believed to enable him to overcome the obstacles in his path. 



Aneura Dumort. 



1. Thallus narrow (about 2 mm. wide), palmately and pinnately 



divided or pinnate or bipinnate. 2. 

 Thallus wider (4 inm. wide (jr more), simple or irregularly lobed. 4. 



2. Calyptra smooth, not tuberculate, more or less hairy or squamu- 



lose, obovate-pyriform, about 'A mm. long. pinnatifida Nees. 

 Calyptra more or less verrucose or tuberculate. '-i. 

 :i. Thallus biconvex with wide margin, formed by a single layer of 

 cells (therefore in transverse section lens-shaped ; caly])tra cylin- 

 drical, 6-8 mm. long. nntltifida Dumort. 

 Thallus Hat, pellucid, with narrow margin (in transverse section of 

 nearly equal thickness or ])lanoconvex) ; calyptra pyriform- 

 clavate. latifrons Lindb. 



