Zoe '-W. S. DUN AND SIR EDGEWORTH DAVID. 
At Letti Paralegoceras is also associated with Propina- 
coceras, the latter being usually considered to be of Lower 
Permian Age. 
The following Brachiopods are also associated at Letti 
with the ammonoids :— 
Productus cora, d’Orb. 
Productus spiralis, Waagen 
Chonetes strophopmenoides, Waagen 
Spirifer rajah, Salter 
Spirifer (Reticularia) lineatus, Martin 
_ Martinia nucula, Rothpletz 
Retzia radialis, Phill., (var. grandicosta, Dav.) 
Notothyris 
Dielasma 
The present opinion of the geologists of the Dutch Hast. 
Indies is that the strata containing the above fossils are 
of Permian, mostly Lower Permian, age and that they are 
stratigraphically superior in position to the Upper Oarbon--. 
iferous Fusulina limestones of the same region. 
EXPLANATION OF PLATES. 
PLATE XC: zane’ 
Gastrioceras Jacksoni, Eth. fil. Specimen showing umbilical. 
region and form of lateral lobes and saddles. Ae 
Puare XII. 
Gastrioceras Jacksoni, Eth, fil. Specimen shown in Plate XT. 
_ Showing suture line and general appearance of septal surface. 
(See text figures 2 and 3). : 
Prats XU. ae 
Gastrioceras Jacksoni, Eth. fil. Ventral aspect of large individual 
), 
i 
y 
showing suture lines, ' 


