FISHES OF FAMILY BLENIsriIDAE 45 



this condition for Blennius gattorugine, but this was not true for my 

 specimen. In the Nemophidinae the ascending wings of the para- 

 sphenoid may reach the descending wings of the frontals, while at 

 the same time the pterosphenoids, which are internal to these struc- 

 tures, may extend beyond the common margin of these wings and 

 enter, somewhat, the orbital region, where the bone can be seen 

 when the skull is viewed laterally (e.g., pi. 8, center and bottom). 

 In Runula, the pterosphenoids typically separate the frontal from 

 the parasphenoid (the illustrated specimen of R. azalea, pi. 8, is 

 exceptional). The character, therefore, is not entirely satisfactory 

 for separating blenniids and clinids, although it does indicate a 

 strong trend. 



In all the Blenniini and Salariini the pterosphenoid is visible when 

 the skull is viewed laterally. In the Omobranchini the pterosphenoid 

 has become greatly reduced and is a very thin bone closely applied 

 to the inner surface of the frontal and sphenotic; it is excluded from 

 view when the skull is viewed laterally. In the Omobranchini the 

 pterosphenoid can be missed easily unless a careful dissection and 

 disarticulation is made. In the Nemophidinae the pterosphenoid is 

 usually in view when the skull is viewed laterally, but in Meiacanthus 

 and Petroscirtes the pterosphenoids are not visible when the skull is 

 so viewed, except that a portion may be visible through the foramen 

 through which the V-VII complex of cranial nerves pass. 



In Meiacanthus there is a unique, continuous ridge formed on the 

 external surface of the ascending wing of the parasphenoid and 

 prootic. The posterior edge of the metapterygoid is attached strongly 

 to this ridge. This attachment greatly increases the immobility of the 

 palatine arch. 



CiRCUMORBiTAL BONES. — The numbcr of circumorbital bones in 

 blenniids varies from two to five and is frequently diagnostic for 

 genera. In the Blenniini, Medusahlennius has two circumorbitals 

 (Springer, 1966), the other genera have five (I, 1955, erroneously re- 

 ported four circumorbitals in Hypleurochilus geminatus). In the 

 Omobranchini, Enchelyurus has three circumorbitals (fig. 13), Cruantus 

 has four, and Laiphognathus and Omohranchus have five (pi. 3). In 

 the salariini all the genera have five circumorbitals except Ecsenius 

 (pi. 9) and an undescribed genus, which have four. (I, 1955, erroneously 

 reported that Entomacrodus textilis and Scartichthys atlanticus'= 

 Ophiohlennius atlanticus had four.) One specimen of Enchelyurvs 

 species and one of Andamia heteroptera each had four circumorbitals 

 on one side and the normal number for the species on the other. In 

 the Nemophidinae the genera all have four circumorbitals (pis. 5, 7) 

 except Meiacanthus, which has three. 



