256 Berycoidei 



occurs at Honolulu. Holotrachys lima is a small, brick-red fish 

 with small very rough scales found throughout Polynesia. 



Fossil species of Holocentrus, Myripristis, and related extinct 

 genera occur in the Eocene and Miocene. Holocentrus macro- 

 cephalus, from Monte Bolca Eocene, is one of the best known. 

 Myricanthus leptacanthus from the same region, has very slender 

 spines in the fins. 



The Polymixiidae. The family of Polymixiida, or barbudos, 

 is one of the most interesting in Ichthyology from its bewilder- 

 ing combination of characters belonging to different groups. 

 With the general aspect of a Berycoid, the ventral rays I, 7, 



(A/ 



FIG. 205. Pine-cone Fish, Monocentris japonicus (Houttuyn). Waka, Japan. 



and the single dorsal fin with a few spines, Polymixia has the 

 scales rather smooth and at the chin are two long barbels which 

 look remarkably like those of the family of Mullida or Sur- 

 mullets. As in the Mullida, there are but four branchiostegals. 

 In other regards the two groups seem to have little in common. 

 According to Starks, the specialized feelers at the chin are 

 different in structure and must have been independently 

 developed in the two groups. In Polymixia, each barbel is 

 suspended from the hypohyal ; three rudimentary branchioste- 

 gals forming its thickened base. In Mullus, each barbel is sus- 

 pended from the trip of a slender projection of the ceratohyal, 

 having no connection with the branchiostegals. Polymixia pos- 



