ESPECIALLY MYCTOPHOIDS 109 
epural is present anterior to the postero-dorsal extension of the stegural. The 
number of principal rays is Ig of which 17 are branched. There are at least 10 
accessory rays epaxially and 10 hypaxially. 
Vertebral column. The vertebral column is shown in the restoration, Text-figure 
47. In the specimens examined the vertebral number ranges from 35 to 40, and the 
centra are constricted. Of the total number of vertebrae approximately 18 are 
precaudal, the remainder (approximately 20) are caudal. The lateral face of each 
centrum bears a pair of longitudinal ridges between which is a rectangular depression. 
The neural arches occupy the entire dorsal surface of each centrum with the neural 
spines arising near to the posterior end of each arch. The suture between the neural 
arch and the corresponding centrum is clearly visible and the most anterior neural 
arches have a tendency to be separated from the centra during fossilization. Pre- 
zygapophyses and postzygapophyses are present on the neural arches but neither 
are particularly prominent. 
pu4 
Fic. 48. Evurypholis boissieri Pictet. Caudal fin skeleton in lateral view. 
The precaudal vertebrae bear paired ventro-lateral transverse processes on the 
anterior end of each centrum. Pleural ribs articulate with these parapophyses, and 
the ribs are moderately long and flattened. The ribs decrease in size posteriorly. 
All of the haemal arches, except for the first, are drawn out posteriorly into haemal 
spines. Epineurals and epipleurals are associated with the first 30 vertebrae. 
Scales. The body is devoid of scales except for a row along the course of the 
lateral line, and three large dermal scutes between the occiput and the dorsal fin in 
the mid-dorsal line of the body. These dorsal scutes are oval in shape and bear 
