cragin.] DESCRIPTIONS OF SPECIES. 43 
metrica, and Astarte malonensis ( f) (of the Theta) — forms which arc 
[themselves the common associates of Trigonia calderoni (Theta and 
Alamitos) ; Astarte microphyes (Theta and Jurassic of Oaxaca), etc. 
SPOlNroYLID.K. 
Genus PLICATULA Lamarck. 
Plicatula SPORTELLA Sp. 11. 
PI. Ill, figs. 8, 0. 
Shell small, well inflated by the convexity of the broadly rounded, 
somewhat inequilateral and twisted, broadly attached right valve; 
left valve nearly flat, its margin rather thick; both valves strongly 
plicated to the correspondingly crenulated margins, the ribs about 10 
on each valve; ribs of the left valve with broadly rounded summits. 
the furrows between them narrow, those of the right valve with nar- 
rower, more widely separated summits, and separated by round- 
bottomed furrows; surface of ribs and furrows on both valves crossed 
iwith imbricated growth lines. 
M< (isurements. — Height, 8 mm.; length, 10 mm.; breadth, 5 mm. 
Occurrence. — Malone Hills, \\ miles east of Malone station. The 
jtype and only specimen is attached to a shell of Nerinea goodellii. 
LIMID/F, 
Genus LIMA Bruguiere. 
Lima interlineata sp. n. 
PI. IV. figs. 5, 6. 
Shell small, obliquely oval, the anterior border straight or very 
slightly convex, the oval being more elongate than that of Lima 
\crenulicosta Roemer, and the lateral profile more nearly approaching 
that of L. wacoensis Roemer; the convexity of the valves, however, 
agreeing more nearly with crenulicosta, and the beaks somewhat 
more elevated than in either of those species; either valve ornamented 
with about 22 radiating ribs; the ribs tectiform, having two faces 
that meet at an angle considerably greater than a right angle; the 
ribs separated by intervals about as wide as themselves, the middle 
of each interval marked by a raised line, or, in the case of a few of 
the posterior intervals, by two to three such lines. It belongs to the 
subgenus Radula. 
Measurements. — Length and breadth of the oval, respectively, L6 
and 12 mm. 
Occurrence. — Represented by a right valve and several fragments 
from locality 1-J- miles east of Malone station, and, of Doctor Stan- 
ton's collecting at same locality, by a left valve with moderately 
