121 



This form typifies a group which numbers among its members some of 

 the smallest species of the genus. It does not appear to be abundant in 

 the State, though it will probably be found more commonly, if sought along 

 the muddy banks of deep streams. 



I'nio iM'trimiK. Gould. Mill Creek, Wabaunsee Co. (Quintard) ; Cow- 

 skin Creek and Little Arkansas River, near Wichita (Mead). 



In Contribution Number III this Unio was listed with a mark of doubt. 

 Further specimens have been received from the above localities, and there 

 is no longer doubt but that the form is true petrinvs. The specimens ob- 

 served place the species in the group of Unio pustuloiu*, Lea, though non- 

 pustulate usually. Two of the specimens now in the cabinet of the reporter 

 show an occasional pustule, though in all other respects there is a most 

 accurate agreement with Gould's description. The species has never been 

 figured. 



Unio phaseoius, Hildreth. Spring River, Baxter Springs (Snow). 



The soft parts of this species are well figured in Jour. Phila. Acad. Nat. 

 Sci., Vol. IV, 2d Series, pi. 29, fig. 101. The species has a rather large 

 synonymy. 



Hiiio piicatus. Le Sueur. Neosho River near Burlington, Ottawa Creek 

 at Garnett, and Verdigris River at Coffeyville (Snow) ; Whitewater River 

 near Towanda (Mead). 



Another undulate Unio. but much flatter, with plications much less ob- 

 lique, more numerous and generally distributed over the major portion of 

 the valves, is often confounded with this species. They do not, as some 

 collectors appear to have imagined, grade each into the other, when num- 

 erous specimens of each, of aU ages, are examined. The related Umo in- 

 dicated, U. undulatus,is more widely distributed than this form, and attains, 

 in the Cumberland and Buck Rivers. Tennessee, its maximum size. While 

 members of the same group, these forms nevertheless should be held as 

 quite distinct. 



Uiiio purpuratus, Lamarck. Kansas River at Topeka (Cragin) ; Ver- 

 digris River at Coffeyville, and Spring River at Baxter Springs (Snow) ; 

 Whitewater River near Towanda. Cowskin Creek and Little Arkansas River, 

 near Wichita (Mead) ; Neosho River (Newlon). 



Unio purpuratus is of quite general occurrence in all parts of Kansas 

 yet explored, which are favorable to Uuiones. Mr. Mead has contributed 

 some of the largest and finest specimens and in the greatest numbers from 

 the Little Arkansas at Wichita. These specimens further contribute ad- 

 ditional data to the synonymy of this genus in that some of the larger 

 Kansas specimens grade into almost or quite typical forms of Unio colura- 

 ftoc.Hsis, Lea, from Texas. The facts all seem to make necessary this dis- 

 position of the last-named Unio. U. ater is also a synonym. 



rnio pnsniiosus. Lea. Verdigris River at Coffeyville, Maraisdes Cygnes 

 near Malvern, and Spring River at Baxter Springs (Snow). 



A Unio which is generally distributed, under various names, from New 

 York to Texas, and northward to Minnesota and Wisconsin. It is the type 

 of an extensive group affording a most fruitful and instructive synonymy. 



Unio rectus, Lamarck. Cow Creek, Hutchinson, Verdigris River at 

 Coffeyville, Solomon River, and Spring River at Baxter Springs (Snow). 



