140 KANSAS ACADEMY OF SCIENCE. 



2. That it possesses some faunal features in common with each of these regions. 



3. That the only faunal region that contributes a considerable majority of its charac- 

 teristic species to any portion of Kansas, is the Central. 



4. That the plains of Kansas, west of the ninety-seventh meridian, possess a large 

 majority — in reptiles and batrachians, perhaps all — of the characteristic species of the 

 Central region, and that while the Central fauna cannot be regarded as extending in full 

 force, except locally, over the plains east of that meridian, many of its characteristic 

 forms occur abundantly further east, some of them ranging to the Missouri river. 



5. That even in the purest portions of the Central fauna in Kansas, appear slight 

 manifestations of Sonoran, and others of Eastern and Austroriparian affinities. 



6. That the prairie fauna of Kansas, east of the ninety-seventh meridian, is a hetero- 

 geneous assemblage of Central, Eastern, and Austroriparian forms, among which the 

 Central predominate. 



7. That it is on the "bottoms" and wooded bluffs, and their immediate vicinity, that 

 the constituency of the Eastern fauna in Kansas is mainly expressed, and that this con- 

 stituency includes comparatively little that is really characteristic of the aquatic phase 

 of that fauna, while representing fairly well the terrestrial aspect of the same. 



8. That the lacking elements of the Eastern fauna in these low and wooded tracts, 

 are largely replaced, in valleys of the Missouri drainage, by Central, and in those of the 

 Arkansas drainage, by Austroriparian and Central elements. 



9. That the constituency of the Eastern fauna in Kansas diminishes westward, and 

 is nearly or quite lost in the Central ere it reaches our western border. 



10. That the Kansas constituency of the Austroriparian fauna lacks numerous charac- 

 teristic forms of that fauna, and is constantly intermingled with Eastern and Central 

 elements. 



11. That this constituency is fullest in the valleys of the lower Arkansas drainage 

 — notably of the Spring, Neosho, Verdigris, and Fall rivers — and represents only the 

 Louisianian and Texan districts. 



PRELIMINARY NOTE ON THE ORIGIN AND MATURATION OF THE 

 OVUM IN PORCELLIO. 



BY F. W. CRAGIN, SC.B. 



The early history of the ovum in Arthropoda is of peculiar interest in relation to 

 Balfour's theory of polar globules. 



In the winter and spring of 1881-2, I undertook an investigation regarding the fate 

 of the germinative vesicle in PorceUio, two writers ( whose names now escape me ) hav- 

 ing claimed to have witnessed a polar globule in this or an allied isopod genus, but their 

 statements being not sufficiently detailed to inspire confidence that the phenomenon wit- 

 nessed was actually what they inferred it to be. 



While the results of my studies were far from conclusive ( and I have since been un- 

 able to resume the investigation), they indicate that events at least potentially equivalent 

 to the formation of polar globules — viz., degradation and partial elimination of the 

 germinative vesicle — probably take place in the maturation of the ovum in PorceUio. 



The ovary in PorceUio is a subcylindrical sac, constituting a conspicuous anatomical 

 feature on either side of and parallel to, the alimentary canal. When not distended 

 with eggs, its diameter parallel to the axis of the upper oviduct is contained seven or 

 eight times in its length. Its wall is a thin, transparent and colorless membrane, appar- 

 ently syncytial, though perhaps really a pavement epithelium with delicate and but 

 slightly differentiated cell-walls. 



