GEMPYLIDAE, LEPIDOPIDAE AND TRICHIURIDAE 23 



Instead of the pterotic and temporal crests being coterminous an- 

 teriorly, the latter ends against the middle of the former, which con- 

 tinues alone to the ridges from the supraoccipital. The epiotics meet 

 very broadly behind the supraoccipital, but a thin sheet of bone from 

 the supraoccipital extends over the median suture between them and 

 reaches down to the exoccipitals. The sheet of bone is so thin and 

 transparent that it is difficult to see it, and the outline of the epiotics 

 is clearly to be seen through it. The ethmoid is not at all posterior to 

 the front of the vomer. The lateral process of the parasphenoid ends 

 as a free point nearly reaching the alisphenoid. The opisthotic sep- 

 arates the exoccipital from the pterotic to a considerable extent, and 

 the lower limb of the posttemporal is attached to its superior surface a 

 little before its posterior edge. The myodome is nearly closed poste- 

 riorly. With these exceptions the cranium is very similar to that of 

 Promethichthys. 



The suborbital ring is incomplete posteriorly, and there is a sub- 

 orbital shelf loosely attached to the bones anterior to it. The preorbital 

 is large and traversed by a sensory tube, which is not in continuation 

 with the suborbitals. 



The maxillary and teeth are essentially as in Promethichthys. The 

 middle portion of the maxillary projects behind in a thin wing, and 

 the supplementary maxillary is not very large. 



The head of the hyomandibular is widely divided into two por- 

 tions. The opercle and subopercle are made up posteriorly of radiating 

 rays of bone, which stand apart like bristles when the tissue connect- 

 ing them is removed. The symplectic is suturally connected with the 

 metapterygoid, and all of the lateral head bones are almost identical 

 with those of Promethichthys. 



As the cranium extends backward below the upper limb of the 

 posttemporal farther than in Promethichthys, the lower posttemporal 

 limb is not in consequence so long. A tube bearing supratemporal is 

 present. 



The portion of the clavicle above the pectoral fin is nearly as long 

 as the portion below, and is turned at a right angle to the latter. The 

 hypocoracoid is thin and much produced backwards. The actinosts are 

 shorter than in Promethichthys, but arranged the same in reference to 

 the coracoid elements, and the arrangement of the postclavicle is the 

 same. 



The pelvic bones are long, simple rays, lying just beneath the skin, 

 remote from the shoulder girdle. The flattened or scale-like ventral 



