CLUPElDiE. 
137 
inferiorly the head is bordered by the great expanded 
preoperculum (p.op.), which has a thickened anterior 
margin and is nearly smooth, marked only very slightly 
by the delicate radiating branches of the slime-canal. 
The right ceratohyal {cli.) and hypohyal are crushed a 
little downwards, the former bearing nine branchiostegal 
rays (&r.), which are laminar in shape but contract to a 
point as they curve to their insertion. The operculum 
(oj?.) is imperfect, but clearly deep and narrow ; the sub¬ 
operculum is not recognizable. The vertebrae are all 
imperfect, but there are distinct indications of the slight 
longitudinal ridges by which the centra are strengthened. 
The ribs are as stout as in Clupea^ and the neural spines in 
front of the dorsal fin are not fused with their respective 
arches. Intermuscular bones occur throughout the trunk 
both above and below the vertebral column. The clavicle 
and supraclavicle are shown to be slender; the postclavicle 
(s.op.) is relatively large. The rays of the paired fins are 
observed to be relatively as robust as those of the caudal; 
the rays of the dorsal fin are more slender. The detached 
anal fin-rays are distinct and shown to be very closely 
divided and articulated ; their supports are connected with 
each other by a process extended along the ventral border 
of the tail. The squamation is well displayed in part, and 
the ventral ridge-scales ajDpear to be destitute of serrations. 
Lewis Coll. 
49487, 49497. Two fine large specimens, slightly deepened by 
crushing; Hakel. The expanded postclavicular plate is 
distinct in both specimens. Many of the intermuscular 
bones in the caudal region are triradiate. Lewis Coll. 
39240, -43. Two large distorted specimens ; Hakel. 
Purchased, 1865. 
48157. Small slab with scattered remains of four individuals; 
Hakel. Lewis Coll. 
P. 8678. Large slab exhibiting numerous distorted and fragmentary 
individuals associated with Diplomystus hrevissimus; 
Hakel. Purchased., 1897. 
49509. Another slab with distorted and fragmentary remains of 
this and other fishes ; Hakel. Lewis Coll. 
