44 U.S. NATIONAL MUSEUM BULLETIN 284 



portions are present and fused except in the single specimen of 

 Blennius canevae examined, where the meningost and belophram are 

 separate). In the Omobranchini the basisphenoid is complete in 

 Lai'phognathuSf Cruantus, Omobranchus loxozonus, and 0. elegans. The 

 belophram is not fused Avith the meningost in 0. anolius and is absent 

 in the other species of Omobranchus and Enchelyurus. The tendency 

 to reduce the basisphenoid in the Omobranchini, as well as other 

 characters (see especially "Jaws and Dentition" below), seems to 

 place this group near the evolutionary line that gave rise to the 

 Nemophidinae. 



In the Nemophidinae, Aspidontus, Blennechis, Petroscirtes, and 

 Runula have a structure that superficially resembles a basisphenoid 

 in shape and position. This structure is formed by the junction of a 

 mesially extending outgrowth of the anterior margin of the pteros- 

 phenoid of each side. These outgrowths meet at the entrance to the 

 braincase and form a tightly interdigitating joint with each other. I 

 term this formation "pseudobasisphenoid" since I first believed it to 

 be a basisphenoid. In addition, each of the pterosphenoids of Runula 

 also have a second, more dorsal, mesially extending outgrowth that 

 fails to meet its opposite. The latter outgrowths are visible in plate 8, 

 bottom. The other genera of the Nemophidinae exhibit the second 

 outgrowths to a much lesser degree than Runula — or not at all. In 

 Meiacanthus, Dasson, and Xiphasia, the more ventral outgrowths were 

 present but failed to meet. In Meiacanthus and Dasson at least, the 

 outgrowths were joined ligamentously. The pseudobasisphenoid forms 

 the anterior roof of the otherwise membranous roofed posterior 

 myodome. 



Rhabdohlennius (Salariini) is unique among the material examined 

 not only in having a complete basisphenoid but also in having mesial 

 outgrowths of the pterosphenoids that meet dorsal to the basisphenoid 

 These outgrowths are comparable in position to the nonmeeting dorsal 

 outgrowths of the pterosphenoids of the Nemophidinae. An unde- 

 scribed genus near Rhabdohlennius has the mesial outgrowths, but 

 these fail to meet. 



In a previous paper I (1966) noted that in the blenniids the as- 

 cending wings of the parasphenoid reach the descending wings of the 

 frontals and, thus, exclude the pterosphenoids from the orbital 

 region. In most of the blenniids this does seem to be the case; however, 

 there are several exceptions, some of which seem to be variations 

 exhibited by individual specimens. I have examined specimens of 

 Blennius cristatus, B. canariensis, Hypleurochilus geminatus, Scarti- 

 chthys gigas, and an undescribed genus related to Rliabdoblennius in 

 which the pterosphenoid of one or both sides separates the para- 

 sphenoid wings from the frontals. In addition, Thiele (1963) reported 



