CHAPTER XXX 

 OPISTHOMI AND ANACANTHINI 



RDER Opisthomi. The order Ofnsthomi (ojticrOrf, behind ; 

 wjjos, shoulder) is characterized by the general traits 

 of the blennies and other elongate, spiny-rayed 

 fishes, but the shoulder-girdle, as in the Apodes and the 

 Heteromi, is inserted on the vertebral column well behind the 

 skull. 



The single family, Mastacembelida, is composed of eel-shaped 

 fishes with a large mouth and projecting lower jaw, inhabiting 

 the waters of India, Africa, and the East Indies. They are 

 small in size and of no economic importance. The dorsal is 

 long, with free spines in front and there are no ventral fins. 

 Were these fins developed, they should in theory be jugular in 

 position. There is no air-duct in Mastacembelus and it seems 

 to be a true spiny-rayed fish, having no special relation to 



FIG. 484. Mastacembelus ellipsifer Boulenger. Congo River. (After Boulenger.) 



either Notacanthus or to the eels. Except for the separation 

 of the shoulder-girdle from the skull, there seems to be no 

 reason for separating them far from the Blennioid forms, and 

 the resemblance to Notacanthus seems wholly fallacious. 



Mastacembelus armatus is a common species of India and 

 China. In Rhynchobdella the nasal appendage or proboscis, con- 

 spicuous in Mastacembelus, is still more developed. Rhynchob- 

 della aculeata is common in India. 



Order Anacanthini. We may separate from the other 

 jugular fishes the great group of codfishes and their allies, 



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