THE NAIADES OF MISSOURI 185 



sculpture faint consisting of fine broad, inverted V-shaped lines with 

 the apices pointing toward tips of beaks; epidermis yellowish 

 or olivaceous with widely separated and interrupted rays. 



Internal Structures: — Cardinals double in left, single in 

 right; laterals doubled the same; nacre white. 



Sex Length Height Diameter Locality 



9 1 10 X 65 X 48mm — (Flat Creek, Sedalia) 



cf 130 X 68 X 48mm — ( " " " ) 



9 82 X 46 X 30mm — (Black R., Williamsville) 



cf 54 X 30 X 17mm — (White R., HoUister) 



Miscellaneous Remarks: — Although L. luteola is considered 

 as having the greatest geographical distribution over all United 

 States yet (strange to say!) it has limited distribution in Missouri. 

 It is not found at all in North Missouri, occurs very sparingly for 

 Central Missouri, (especially in the Osage basin) and is not at all 

 typical for South Missouri. The best types are found in Crow's 

 Fork, Fulton, and in Flat Creek, Sedalia, where the female shells 

 attain enormous size and thickness — the typical "Fat Mucket," 

 as it is known on the market. Surber finds that the glochidia of 

 luteola attain a larger size in the fluviatile forms (191 2, p. 4) and 

 thinks that the larger size of the river form may be correlated with 

 the larva. Luteola is bradytictic. 



Lampsilis luteola rosacea (DeKay). 



("Rosy Mucket.") 

 PL XXVIII, Figs. 104 A and B. 



1843 — Unio rosaceus DeKay, Zool. of New York, V., p. 192, pi. XXXIV, 



figs. 355 and 356. 

 1900b — Lampsilis luteolus rosaceus (DeKay) Simpson, Pr. U. S. Nat. 



Mus., XXII, p. 535. 



Animal Characters: — No soft parts have been seen but in 

 all probability identical with those of the parent. 



Shell Characters: — Identical in all respects with the parent 

 species except in its solid pink nacre. 



Sex Length Height Diameter Locality 



cf 125 X 72 x 49mm — (White R., Hollister) 

 9 90 X 52 X 37mm — (Black R., Williamsville) 



Miscellaneous Remarks: — A cotype from a lot of pink- 

 nacred shells collected by the writer in the White and Black 



