422 NOTES ON FLORIDA UNIONIDA—SIMPSON. 
Unio denigratus Lea. 
(Plate Lxv, Fig. 1.) 
Unio denigratus, Lea. Obs. vu, p. 18, Pl. xxi, Fig.83, June 23, 1857, Streams near 
Columbus, Ga.; Bishop Elliott. 
This species is close to U. tortivus, and the young can hardly be sep- 
arated at times, but it seems to differ constantly in being more rhom- 
boid when adult, approaching the form of Margaritana calceola. Ihave 
it before me from Lake Monroe and St. Augustine, collected by F. 
Rugel, and now in the collection of Mrs. Andrews, 
Unio insulsus Lea. 
(Plate Lxv, Figs. 1, 5.) 
Unio insulsus Lea. Obs. vit, p. 57, Pl. 1, Fig. 199. Roanoake R., N. C.; Prof. Em- 
mons. 
A small, inflated species, greenish brown, and obscurely rayed, and, 
as Dr. Lea remarks, very closely related to U. confertus. I am inclined 
to believe it but the young or a small form of the latter, as the differ- 
ences seem to be that U. confertus is larger, and with age becomes 
~black, and is in some examples not greatly inflated. Lea has a speci- 
men of the species under consideration from Savannah. In Mrs. An- 
drews’s collection there is a shell collected by Rugel, and labeled 
“Florida,” which is evidently this. 
Unio Cunninghami B, H. Wright. 
(Plate Lxv, Fig. 6.) 
Unio Cunninghami B. H. Wright. Proe. Acad. Nat. Sci., Philadelphia, 1883, p. 58, 
Pl. 1, Figs. 1, 2,3, and 4. Sumter County, Fla. 
This species is very commonly sent out as Unio Buddianus or Buck- 
leyi, but is really one of the most distinet in Florida. 
Itis a solid, greatly inflated, triangular shell, wide at the anterior 
end, and rapidly tapering from just behind the beaks to the posterior 
ventral region; the dorsal line being curved, the ventral straight or 
even arcuate. The color varies from greenish or yellowish ash to chest- 
nut black, generally shining, and very rarely faintly rayed; the teeth 
are Strong and ragged; nacre brilliant, and varying from silvery to 
purple. One specimen before me labelled “ Florida,” and belonging to 
Mr. Marsh, is almost jet black, 1.25 inches in length and 1.80 inches 
wide, and is as ponderous as any adult crassidens. Young shells are 
sometimes very much like Unio micans, but are generally solider. So 
far as I know the species is confined to the lake region. 
