374 LABYRINTHICr. 



3. ANABAS*. 



Anabas, Cuv. Regne Anim. 



Body compressed, oblong ; preeorbital and opercles serrated ; cleft 

 of the mouth extending to, or below, the orbit. Small teeth in the 

 jaws, on the head of the vomer and on its posterior portion ; none 

 on the palatine bones. Dorsal spines mimerous (sixteen to nineteen) ; 

 anal spines in moderate number (nine to eleven) ; ventral fins com- 

 posed of one spine and five rays : none of the fins elongate. Lateral 

 line inten-upted. Branchial arches with toothed tubercles. Air- 

 bladder bifid posteriorly, each lateral portion extending nearly to the 

 end of the tail. Pyloric appendages in small number. Intestine of 

 moderate length. 



Freshwater fishes of Tropical India : said to be able to ascend trees. 



It is extremely difficult to distinguish the difi'erent species of this 

 genus. 



1. The most reliable of the character is the difference in the 

 number of the scales of the lateral line, which, small as it is, is 

 found constant in all the individuals of the same species. Therefore 

 Anabas oligolepis, Bleek., from Borneo, or the Ceylonese Anabas, if it 

 be a species distinct from the former, is different from A. scandens. 



2. Much more questionable are the characters taken from the 

 form of the body. Not only is the body more elevated in yoimg 

 individuals than in adult ones, but also in those which had a full 

 supply of food at the time they were caught ; there are specimens 

 in the British MuSeum which by their lean appearance show that 

 they had fasted for some time, and these have the body elongated, 

 like Bleeker's A. macrocephalus, although they certainly belong to 

 the true A. sbandens. 



3. The degree in which the delicate laminae composing the super- 

 branchial organ are developed is dependent on age. It is not im- 

 probable that this organ, in its highest perfection, is somewhat more 

 developed in one species than in the other ; biit young individuals 

 always show it less complicated than half-gTown ones of the same 

 species, and these, again, less than old onesf. I have arrived at this 

 conclusion after the examination of more than twenty individuals : 

 having, however, a complete series only of A. scandens, I restrict 

 myself to a description of the development of this organ in that 

 species. 



The superbranchial organ is formed by several exceedingly thin 

 bony laminae, similar in form to the auricle, and concentrically situ- 

 ated one above the other, so that the innermost is the largest. Now, 

 in specimens from one inch and a half to two inches and a half long, 

 there are only two such laminae, a third being indicated by a small 

 protuberance at the central base of the second or outer lamina. In 

 specimens of from three to four inches in length, the third lamina is 

 developed, covering one-half of the second. The edges of all the 



* 1. Anabas variegatus, Bleek. Celebes, i. p. 220. — North Celebes. 

 t The same is the case in Osphromenxis olfax, and probably in all the fishes of 

 this family. 



