Lew and Little Known American Paleozoic Ostracoda. 179 
ISOCHILINA AMPLA, DN. sp. 
Lige, NI Haes.. 3 00). C,. as 
Length, 17.8 mm.; height, 13.0 mm.; thickness of one valve, 6.0 mm. 
66 21.4 ‘é cc ; iO “6 
Size: 
Carapace large, oblique, widest posteriorly, unusually high, and 
strongly convex, with point of greatest convexity very near the 
center. Dorsal edge straight, long, obtusely angular behind, 
pointed in front. Flange distinct, narrow in front, wanting at the 
ventral edge, and of moderate width behind. Ventral region 
tumid, descending abruptly to the edge. Dorsal slope very abrupt. 
Eye tubercle distinct but rather small. Just behind it a slight 
depression, and beneath the latter the oval reticulated spot. (Not 
shown in fig. 8a.) Surface polished, apparently without puncte or 
ornament of any kind. Internal characters as shown in fig. 8d. 
This fine species is larger, higher and fuller than any other so 
far known from American rocks. J. jonesz, Wetherby, which 1s 
perhaps more nearly related than any of the others, differs prin- 
cipally in being less high, and in the outline of the ventral edge. 
Position and locality: Upper beds of the Trenton limestone at 
Nashville, Tenn. b 
ISOCHILINA JONESI, Wetherby. 
late NI) fies... 9) a, 0, Cc: 
Tsochilina jonest ,Wetherby, Jour. Cin. Soc. Nat. Hist., Vol. IV, 
be 50, room 
This species, of which the above cited illustrations represent the 
largest example seen, is very abundant in the massive gray lime- 
stone forming the top of the Trenton near Harrodsburg, Ky. The 
same hed contains Leperditia linneyt, L. appressa, and other Ostra- 
coda. ‘The specimen figured is perhaps a very little higher than 
usual, but the difference is so small that we may with propriety 
regard it as a typical example of the species. 
ISOCHILINA KENTUCKYENSIS, Nn. sp. 
Pee HES. TT a,.0. 05. a. 
Compare Leperditia (Lsochilina) armata, Walcott, 35th Rep. N. Y. 
St. Mus. Nat. Hist., p. 213, 1883. 
Size of left valve: Length, 4.9 mm.; height, 2.66 mm.,; thick- 
ness, 0.83 mm. 
