ESPECIALLY MYCTOPHOIDS 229 
represented in the ctenothrissiforms or the beryciforms. A list of certain basic 
differences between the two lineages is given below : 
Myctophiformes Ctenothrissiformes 
Paracanthopterygii Beryciformes 
1. Very long alveolar process of the premaxilla Alveolar arm much shorter 
under the maxilla. 
2. No teeth on the maxilla. Teeth on maxilla in ctenothrissids and 
certain berycoids. 
3. Supramaxillae small or absent. Supramaxillae always present and large. 
4. No subocular shelf on infraorbital bones. Subocular shelf present on infraorbital 
bones. 
5. Adipose fin present in myctophiforms Adipose fin never present. 
and Percopsidae. 
6. Undeepened body. Body much deepened in the beryciforms. 
Together with these differences, Greenwood, et al. (1966, p. 388) have pointed out 
several differences concerned with the levator maxillae muscles and the recurrent 
facial nerve. 
The condition of the caudal skeleton in the paracanthopterygians is unusual 
(Gosline, 1961, 1963 ; Rosen, 1962). Instead of the normal fusion of the ural 
vertebrae with the first preural vertebra followed by subsequent fusion of the upper 
hypurals to this compound centrum, as has occurred in most higher teleosts, the 
paracanthopterygians have the upper hypurals fused to the second ural vertebra 
and this vertebra retains its intervertebral articulation with the fused first preural 
and ural vertebrae. This condition is approached by certain of the advanced 
myctophiforms such as Neoscopelus, but by none of the beryciforms. Sardinioides 
is also similar and additionally has a gap between the second and third hypurals, a 
feature noticed in many paracanthopterygians. Among other fossil forms Volci- 
chthys, noticed earlier (p. 226, Text-fig. 98), has a caudal skeleton closely approaching 
that of certain amblyopsids. The second ural vertebra has fused with the upper 
hypurals, while the fused preural and ural vertebrae support the fused first two 
hypurals as well as the parhypural. A prominent gap is also present between the 
second and third hypurals. Possibly Volcichthys and the related Sardinius are 
close to the ‘ paraberycoid’ hypothetical assemblage, additional support being 
added by the presence of well developed ctenoid scales in Sardinius. 
Order CTENOTHRISSIFORMES 
The new genus Pattersonichthys has been erected to contain several small specimens 
from the Middle Cenomanian of Hajula, Lebanon. The genus clearly belongs in the 
order Ctenothrissiformes showing those characters enumerated by Patterson (1964 : 
244) for the order. The primitive features visible in Pattersonichthys are as follows: 
1. Antorbital present. 
2. Orbitosphenoid present. 
3. Premaxilla small, but with a developing ascending process. 
