62 U.S. NATIONAL MUSEUM BULLETIN 284 



of which is the most easily described: the coracoid is reduced and 

 fused (synostosis) to the cleithrum. Usually there is no remnant of 

 a joint line between these two bones. All other blennioids have an 

 unreduced and distinctly separate coracoid. 



The second character concerns the relationship of the interopercle 

 with the epihyal and subopercle. I (1966) briefly discussed this as 

 a family character and Thiele (1963, pp. 386-387; fig. 28) described 

 the relationship in some detail for three species of Blennius. The 

 posterior end of the interopercle and the ventral end of the interhyal 

 form a ligamentous, tight connection with a prominence on the 

 posterolateral surface of the epihyal. In all blenniids except the 

 Omobranchini, which comprises only a few species, the posterior 

 end of the interopercle is anterior (even though only sHghtly) to 

 the posterior end of the epihyal (fig. 16a). In the Omobranchini the 

 condition is essentially the same except that there has developed, 

 probably secondarily, a posteriorly projecting spur on the ventro- 

 posterior end of the interopercle (fig. 16b). 



The blenniid interopercle is greatly reduced and is internal to the 

 ventral portion of the preopercle (no portion of the interopercle and 

 subopercle are in bony contact although they are Hgamentously 

 attached). The interopercle is not normally visible when the skull 

 is viewed laterally. The reduced nature and peculiar relationships 

 of the interopercle probably caused Pinto (1959) to report that the 

 interopercle was absent in blenniids. In the nonblenniid blennioids 

 except Chaenopsis, the interopercle overlaps and extends posterior 

 to the posterior end of the epihyal, and the interopercle is usually 

 apparent when the skuU is viev/ed laterally. In Chaenopsis the pos- 

 terior end of the epihyal has been raised considerably, relative to 

 its anterior end. The interopercle has retained its normal position 

 and is not joined closely to the epihyal; the posterior end of the 

 interopercle is well below and anterior to the level of the posterior 

 end of the epihyal. In no case, however, is there a dupUcation in 

 any of the nonblenniid blennioids of either of the two interopercle- 

 epihyal relationships found in the blenniids. 



The third character lies in the nature of the dentition. Anteriorly 

 on the dentaries and premaxillaries, the blenniids (adults) have a 

 single row of evenly aUgned, close-set (no space between teeth 

 distally) comblike teeth. Normally there are no functional teeth, 

 viUiform or otherwise, behind the anterior row in either jaw. Pos- 

 teriorly on the dentary or premaxillary, straight or recurved canines 

 may be present. The canines may be greatly enlarged or scarcely 

 larger, more pointed or more blunt, than the comblike teeth. Teeth 

 are never present on the palatines and are present on the vomer 

 of only a relatively few species. In contrast to the blenniids, the 



