223 
spine, which is not denticulated, scarcely or not longer than 
postorbital part of head. Teeth in the jaws in a broad curved 
band, those of the vomer in a very short elliptic band. 
Length about 240 mm. [Type in Leyden Museum examined]. 
Nomen indig.: Lais puti (Mal. Banjerm.). 
Habitat: Java (Krawang); Borneo (Banjermassin); Sumatra 
(Palembang). — Siam. 
In fresh water. 
3. Fam. PLOTOSIDAE. 
Elongate, tail tapering. Head depressed. First dorsal fin 
above or behind origin of pectorals, with a spine, which is 
smooth, serrated on both edges or only along the hindborder. 
No adipose fin, but a long or short so called second dorsal 
or caudodorsal, probably a procurrent part of the caudal, 
confluent with the caudal and often beginning with a fat 
pad. Anal many-rayed, confluent with pointed caudal. Ven- 
trals with 1o0—12 rays. Pectorals with a rather weak or 
with a strong pungent denticulated spine. Nostrils remote 
from each other, the anterior ones generally tubular, in the 
frontborder of the upper lip and looking up or forward, or 
perforating it and looking downward. Posterior nostril a slit 
behind the nasal barbel. A pair of maxillary, mandibulary 
and mental barbels; besides a lateral fold at the corner of 
the mouth may be produced in a short barbel. Conical teeth 
in the jaws, which may be wanting in the upper jaw and 
mixed with molar-like ones in the lower jaw; on the vomer molar- 
like or conical in a patch or band. Lateral line more or less 
conspicuous by distant pores. Axillary porus present or absent. 
A dendritic organ between anus and anal present or absent. 
Gillmembranes united or more or less separated from each 
other, totally or partly united with isthmus or free from it. 
First branchial arch besides gillrakers, without or with a 
membrane, the free edge of which is fringed or has rounded 
processes, which may get independent. 
iscy. tothe genera. 
I, A. praeanal dendritic organ. 
1. Anterior nostril perforating upperlip near its anterior 
border and looking downward. Origin of second 
