Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 498 
Family. RAJIDZ. 
Genus. Raja. 
Disk broad, rhombic, generally with asperities. Two dorsal fins on the tail, 
without spine. Tail with a rudimentary caudal fin, or without caudal. Each 
ventral fin divided by a deep notch. ‘Teeth small, obtuse, or pointed. Pectoral 
fins not extending forwards to the extremity of the snout. Nasal valves separated 
in the middle, where they are without a free margin. (Giinther.) 
Raja minor, Davis. 
(Elsa; fis./2:) 
An exquisite little specimen, collected by Mr. Lewis, and now in the British 
Museum, is from the soft cretaceous beds of Sahel Alma. The length of the 
fish from the tip of the snout to that of the tail is 2°6 inches; its breadth 
across the pectoral fins is 2°2 inches. The pectoral fins are large, extending 
anteriorly beyond the orifice of the mouth, but not encircling the head. The 
whole of the dermal covering has disappeared, leaving the internal framework 
of the fish fully exposed. ; 
The cavity of the head is nearly circular and 0-9 of an inch in diameter. 
The mouth is placed 0:4 of an inch from the end of the snout and 0°5 in 
front of the pectoral arch. It is large, 0°6 of an inch across, and is armed with 
a series of minute teeth, conical and accuminate in front, and somewhat flattened 
and expanded laterally. A broad flat bone extends between the buccal region 
and the pectoral arch; there is no evidence preserved of the branchiostegal rays. 
Anteriorly to the upper jaw there is a cartilaginous extension, broad at its base, 
but dividing into filamentous prolongations. 
The thoracic cavity extends 0°35 of an inch backwards and is 0°6 of an inch 
across. Anteriorly it is bounded by the scapular bones, which are large and 
strong. Ata distance of 0:3 of an inch from the vertebral column a very strong 
branch extends anteriorly and encircles the cavity of the head; a second and 
smaller one extends posteriorly, enveloping the thoracic cavity. From these 
bones the pectoral rays, fifty-eight in number, on each side are radiated. The 
rays are fine and slender, and dichotomize towards their distal extremity. The 
base of the pectoral fin extends forwards to a position in front of the month 
and backwards to the pubic bones a distance of 1:1 inch. The longest central 
rays are 0°7 of an inch in length: the external margin of the fin is circular. 
TRANS. ROY, DUB. SOC., N.S. VOL. III. 3 WY 
