SIMPSON — CONTRIBUTIONS TO THE MOLLUSCA OF FLORIDA. 67* 



Manatee River, with the next. In old specimens the outer edge of the 

 shell is sometimes greatly thickened. It goes to Cape Hatteras, and is 

 there found fossil. 



Plenromeris tridentata (Say.) Con. Dredged living, abundantly, at 

 the mouth of the Manatee. Occasionally found dead, washed up on 

 Kgmont. 



* Unio aheneus Lea. Palatka, J. B. Upson ; Gainesville, S. H. Wright. 



* Unio aquilus Lea. Palatka, Upson. 



Unio buckleyi Lea. Miakka Upper Lake, Manatee County, abun- 

 dant and variable. A smaller and more inflated form was received from 

 Mr. Cunningham, from Sumpter County. 



* Unio blandingianus Lea. Gaylor Creek, Brevard County, Cun- 

 ningham ; Florida, without locality, Mr. William A. Marsh. 



* Unio buddianus Lea. Orange County, Mr. Harry A. Pilsbry. 

 Unio concavus Lea. Miakka Upper Lake; East Florida, Cunning- 

 ham; Orange County, Pilsbry. 



* Unio cunninghami Wright. Volusia County, Cunningham; same 

 locality, Pilsbry. Very close to forms of U. buckleyi. 



* Unio floridensis Lea. Volusia County, Cunningham. 



Unio fiiscatus Lea. Very abundant in Horse Creek, Manatee 

 County; Sumpter County, Cunningham. Received from other corres- 

 pondents from various parts of the state. It appears to be a very com- 

 mon species. 



Unio hebes Lea. Dry Branch, emptying into Ware's Creek, Manatee 

 County. This little drain in the pine woods only contained water 

 during the wettest part of the rainy season, not over three months in 

 the year, yet in it I found thousands of living specimens, and a few 

 which Mr. Marsh has identified as U. bissellianus Lea. They were 

 only found along an extent of some ten or a dozen rods, and often dug 

 out of dry sand; not a specimen was taken out either above or below 

 this limit. Some of these which were taken out and laid in the grass in 

 a sunny place, survived over three months without a drop of water. 



Unio jewettii Lea. Miakka Upper Lake, Manatee County. U. 

 jewettii, U. blandingianus, and U. hebes are close species, but I have 

 always been able to separate them. 



Unio nigrinus Lea. Horse Creek, Manatee County; Orange 

 County, Pilsbry. 



* Unio ocmulgeensis Lea. Lake Beresford, S. H. Wright. 

 Unio paulus Lea. Horse Creek, Manatee County. 



* Unio lepidus Gould. Lake Beresford, Wright. 



* Unio obesus Lea. Lake Beresford, Wright. 



Unio sudus Lea. Miakka Upper Lake, Manatee County. 

 Unio vesicularis Lea. Horse Creek, Manatee County. 



* Unio rostriformis Lea. Florida, without locality, Upson. 



