SOCXOP.'EA GliANDIS. 
Genus SOCNOP^A, Stromcr. 
[Neues Jalirb. 1904, vol. i. (Abliandliingeii) p. (!.] 
This genus was founded by Stromer for the reception of a single species of large 
Siluroid from the Qasr-el-Sagha beds. The basioccipital is said to bear paired 
processes for union with the post-temporal, as in Bagnis, to which this form is 
probably nearly related. 
Socnopaea grandis, stromer. 
1904. Socnopcca grandis, Ernst Stromer, Neues Jalirb. vol. i. (Abhandlungen) pp. G-7, pi. i. 
fig. 3. 
Tgpe Specimen. — An imperfect skull ; Palmontological Museum, Munich. 
This species seems to have attained a very large size. The sculpturing of the skull- 
roof differs widely from that of Fajuinia, and consists of numerous small tubercles 
arranged in longitudinal lines, there being no rows of specially enlarged tubercles at 
tlie sides of the median depression. This latter is long and sharply defined ; into it 
there open two fontanelles, one near its anterior end, the other near the middle. The 
supraoccipital region projects considerably behind the rest of the skull. 
Form. & Loc. — Qasr-el-Sagha beds (Middle Eocene) : north of Birket-el-Qurun. 
C. 10199. Skull and large part of the skeleton of a very large individual. The principal parts 
preserved are : — (1) Skull, somewhat incomplete towards the outer angles of its 
anterior end, showing the characteristic sculpture ; (2) portions of the mandible and 
hyomandibular ; (3) part of the vertebral column, including the anterior complex 
vertebra and a series of about nineteen others ; (4) the interneural plate with the 
dorsal spine ; (5) portions of the two halves of the shoulder-girdle wdtli the pectoral 
spine. This specimen shows that these Eocene Siluroids attained a large size, the skull 
being about 65 cm. long, about 21 cm. wide posteriorly, and 32 cm. wide in front; the 
length from the basioccipital to the tip of snout is 5(y5 cm. The complex vertebra 
is about 15 cm. in length, and the vertical diameter of the anterior end of its centrum 
about 5'7 cm. The arrow-head-shaped interneural plate is large, its length in the 
mid-dorsal line being 11 cm., length to posterior angles 17 cm., greatest width upwards 
of 12 cm. Its dorsal surface is covered wdth an ornamentation of rounded tubercles 
arranged more or less in lines, and rather larger and more prominent than those on the 
skull-roof. The posterior notch is occupied by the small supporting spine of the usual 
form, and behind this by the large dorsal spine; this was probably about 20 cm. long 
and curved backwards ; it seems to have had a tuberculate anterior border and sides 
marked by fine irregular ridges. The width of the base of this spine from side to side 
is 4’3 cm., the width of its middle region from before backwards about 2'5 cm. The 
2s2 
