365 



between the occipital process and the basal shield of the 

 dorsal spine; head longer than broad, a little broader than 

 deep; snout not prominent. The depth of the body contained 

 five times in the total length (without caudal), the length of 

 the head thrice and two thirds. Barbels slender and short, 

 the maxillary reaching the opercle. Dorsal spine serrated be- 

 hind, its length two thirds that of the head. Adipose fin 

 twice as long as dorsal, as long as its distance from the 

 latter. Pectoral spine strong, considerably longer than the 

 dorsal, strongly serrated on the inner edge. Brown above, 

 fins blackish brown. Length 90 mm. [After Boulenger, not 

 seen by us]. 



Habitat: Sumatra (Deli). 



7. Fam. AKYSIDAE. 



More or less elongate, belly flat, skin covered with roundish 

 granules or tubercles, which may be arranged in longitudinal 

 rows. Head depressed, with or without prominent longitudinal 

 ridges, covered by soft skin. A median longitudinal fontanel 

 present. Anterior nostrils tubular, at some distance from the 

 posterior ones, which have a circular rim, the frontborder of 

 which carries a nasal barbel. A pair of maxillary, mandibulary 

 and mental barbels. Snout slightly prominent before the trans- 

 verse or curved mouthopening. Short dorsal with five soft 

 rays and one or two pungent spines, covered by skin, placed 

 anteriorly, between pectorals and ventrals. Adipose fin absent or 

 present, in latter case opposite to short anal. Ventrals 6-rayed, 

 horizontal, as also the pectorals, which have a strong osseous 

 spine. Caudal truncate or deeply emarginate. Villiform teeth 

 in the jaws, none on the palate. Gillmembranes united with 

 each other and with the isthmus. Gillopening narrow, extending 

 dorsally to the base of the pectoral or above it. Branchiostegals 6. 



Key to the genera. 



I. Adipose fin present. 



a. Gillopening extending dorsally only to the base 

 of the pectoral. Caudal truncate or slightly 

 emarginate Acrochordonichthys p. 366. 



