Morgan Expeditions. 114 
The first distinguishing feature of this species lies in the 
great prominence of the test, none of the forms, with which 
we have compared it, approaching it at all in convexity. 
This difference of character is supplemented by many others. 
From Dalmania Boothii, of the Hamilton group of New 
York, the only abundant form known in beds corresponding 
most nearly in age to the Ereré Devonian, it differs, among 
other features, in the greater proportionate length of the 
middle of the head, in the more gradual backward _nar- 
rowing of the glabella, and in the greater length of the 
frontal lobe, which is generally more angular in front in 
the latter form. 
This beautiful species occurs somewhat abundantly in the 
Devonian sandstone at Ereré, associated with Spirifera Ped- 
roana, etc. The specific name is given in allusion to a 
mythical personage, after whom the Serra of Paittina’ in 
the vicinity received its name. 
Genus HOMALONOTUS, Keenig. 
Homalonotus Oiara, sp. nov. 
There was obtained from the Devonian sandstone at Ereré, 
a single fragment of the head of a large trilobite, which be- 
longs to this genus. It is very distinct from any other form 
yet known, but too imperfect to admit of proper descrip- 
tion. It differs from Lomalonotus Dekayi, Vay., appar- 
ently, in the fact that the margins of the glabella are more 
concave than in the latter form, and the eyes are placed 
farther forward. We have ventured to rank it as a new 
species, naming it after the Tupi water maiden. Associated 
with the last species above described, Daliania Paitina. 
GASTEROPODA. 
Genus PLEUROTOMARIA, Defrance. 
Pleurotomaria Rochana, sp. nov. 
Shell quite small; outline, as seen in front and hind view, a rhomboid, 
of which two opposing sides are about twice the length of the other two 
