464 



SILURIM. 



than postocular part of head ; eye nearly lateral, 3 to 4 times in length 

 of head, 1 to If times in interorbital width; lips moderately developed ; 

 prte maxillary teeth small and wide apart, forming a short and broad 

 band; movable mandibular teeth i to ^ diameter of eye, 8 to J 2 in 

 number. Maxillary barbel with a broad marginal membrane at the 

 base, as long as head or a little shorter, reaching root of pectoral spine 

 or a little beyond ; mandibular barbels with ramified obtuse branches, 

 outer only a little longer than inner. Gill-opening not extending 

 downwards beyond root of pectoral spine. Occipito-nuchal shield 

 granulate like the occiput, obtusely tectiform, 1 J times as long as broad, 

 posterior processes rounded. Humeral process not or but slightly longer 

 than broad, flat, feebly granulate and striated, rounded or truncate 

 behind, extending as far back as occipito-nuchal process. Dorsal I 7 ; 

 spine straight or feebly curved, as long as or a little longer than head, 



Pig. 348. 



Synodontis nummifer. 

 Type (A. M. C). f. 



smooth in front, feebly serrated behind. Adipose dorsal about 4 times 

 as long as deep, If to 2 times as long as its distance from rayed dorsal. 

 Anal III 7-8, pointed. Pectoral spine a little shorter than head, strongly 



