— 333 — 
four-sevenths. The fore-arm-arm ratio. is. about one to two in both 
types. 
The discovery, in the Brasilian ‘Permian, ofa form Having closer 
morphological affinity to Mesosaurus of the South African Karoo 
beds than to its geographical near neighbor, the Brasilian Stereos- 
ternum, is of considerable interest, though not surprising in view of 
the well-known general correspondence in the Permian -faunas of 
the two regions, At present there is no basis for the generic sepa- 
ration of the new form from M. tenuidens, but since the latter species 
is not yet completely known further. knowledge concerning it (e, g., 
the thoraco-lumbar vertebral formula) may necessitate pa erection 
of a new genus for M. brasiliensis: pe ae 
_ ABREVIATIONS USED IN THE FIGURES 
Meh 2s Ge a 4 Ablominal ribs. 
Art. 6. 1 1 ee . Articular. . 
Cl... . 2... . . « Clavicle, 
Co. s « « + «© «is «4» Coracoid. F 
Es < 6 ¢ 5,9 Cow eo Bilal | 
Fm...... .. =° «. Femur. 
Hu... ... . +. «. . Humerus. 
Tl, ely «.e« «= ae @ Inbenglayicle, 
Tl. we 6 6 be ow ve, © Slim. | een ; 
Is. 2. we ew ew wh he 6h, ISchium. ' ee 
-Md. s . . 2.2. + 4... ~ ;Mandible. 
Mx... . 2 «| © « «©. Magilla. , 
eNews wh cere aa wey a og Nearse ce 5 
Na. . » © « «© «©, +. « » Nasal. 
Os 6 « & @ wy 8,8 «© + «Orbit, 
Phe: 3s: Som Ow eR ee _Pubis. ae 
P. Mx... ... . . ~~ Pre-maxilla. 
Q.... . + « . « © Quadrate. 
Ress eo oh GS) Seo? woe coe: GRadius: 
Sa... . . « . + . . Sacral vertebra. 
Sc. . 2. 2. «© + . « . . Scapula 
Tyce Boren a , cae GS, Sas 
Ue. wv ick Bose woe ce we Ulinas 
