BllACHIOPODA. 
20 
form (fig. 4) are faint even in the concave valve, are here 
strong and well marked, so as to decussate the longitudinal 
ribs or striae. These longitudinal ribs, though fainter in this 
variety than in the typical form, are nevertheless present, the 
difference being solely in the ornament. 
Such variations are common in all Brachiopod shells : yet 
ornament is, in truth, a more constant character than form. 
There can be no fixed rule for discriminating the characters ot 
species. 
Locality .—Chorhoti Pass, 17,000 feet, (No. 1741.) 
LEPTiENA REPANDA. 
Plate 3, fig. 3. 
L. semitmcialiS, quarn semiovali latior, valde involuta rugato- 
undulata, costis seu rugis validis 5-7, liaucl nates attingentibus. Valva 
concava lee vis, sulcis jugisque quibusdam costula unica ornatis. 
Fully half an inch wide, highly convex, semi-oval, but with 
long produced ears. Seven very strong folds or ribs undulate the 
surface, of which the central one is by far the widest and deep¬ 
est : they reach about half-way from the front to the beak. 
Coarse and rather obscure striae run with the ribs, and on the 
concave valve one strong rib runs along each furrow, and one, 
a fainter one, along the centre of the ridges. These appear of 
course on the intaglio as furrows, and our specimen figured is 
the impression of the outer surface of the concave valve 
(magnified at 5 a). 
No transverse striae show on three specimens. 
It is a pretty shell, well characterized by the great width, 
and extended ears, and especially by the five or seven broad 
deep undulations which reach half-way from the margin to 
the beak. 
Locality. —Damchen, 1G,000 feet. (No. 1678.) 
