52 U.S. NATIONAL MUSEUM BULLETIN 284 



diagnostic of, the Anarhichadidae (Barsukov, 1959) of the northern 

 blennioid superfamily Zoarceoidae (o/ Gosline, 1968). Runula further 

 is peculiar in the Blenniidae in that the nasals, median ethmoid, and 

 lateral ethmoids have become fused to the fronatls, effectively 

 forming a strong, solid block of bone anteriorly on the skuU. The ex- 

 ternal joint lines of these bones are evident since the synostosis has 

 taken place internally only. 



There is a tendency among the Nemophidinae for ornamenta- 

 tion of the skull bones, particularly the frontals. The ornamentation 

 ranges from tiny, shallow depressions in Runula (pi. 8) to large, 

 deep holes in Aspidontus (pi. 6). The excavations are filled with 

 connective tissue. The reason for this ornamentation is not clear 

 although it may be a response to the free-swimming habit of these 

 fishes: a method of decreasing the weight of the bone. 



Typically in the Blenniidae, the parietals meet only at a 

 point just anterior to the median, predorsal pore of the supratemporal 

 canal. The parietals are otherwise separated by the supraoccipital 

 and frontals. In Aspidontus (pi. 6), Blennechis, Dasson, and Petro- 

 scirtes, the parietals meet for a relatively greater distance and the 

 pore opening is either anterior to or between the parietals, In some 

 species, Andamia hete7'optera (pi. 11), for example, the supraoccipital 

 completely separates the parietals, and the pore opens through the 

 supraoccipital alone. Frequently in juvenile blenniids the parietals 

 fail to meet, so that the circumstance in Andamia may be the result 

 of neoteny. In a number of Salariini and Omobranchini the meeting 

 of the parietals on the dorsal skull surface isolates an anterior island 

 of the supraoccipital from the main body of the supraoccipital (pi. 

 4, upper; 10, upper). 



Bony crests, formed by the midline meeting of the frontals 

 and parietals of each side and along the posterior margins of the 

 parietals and pterotics, are absent in juveniles, appearing gradually 

 with the increase in size of the individuals of many species. 



Lateral Extrascapulars: In the blenniids the only pair of extra- 

 scapulars present is the lateral extrascapular pair. These are present 

 in all genera except Ecsenius (pi. 10), Petroscirtes, and one of two 

 specimens of Dasson, wherein there has been a synostosis of the ex- 

 trascapulars with the pterotics, and Runula (pi. 8), wherein the syn- 

 ostosis has been with the parietals, with complete loss of any indica- 

 tion of a joint line. In many blenniids the lateral extrascapulars may 

 become encapsulated secondarily and lost from view in large specimens 

 of a particular species when the pterotic-parietal crests, together 

 with the epiotic facet for articulation with the posttemporal, close 

 over them. 



Intercalar: The intercalars are present in all the Blenniinae and 

 absent in all the Petroscirtinae except Dasson, 



