NOTES. 1 45 



vast multitude of small tadpole-like fishes, moving in unison, each 

 one cliaracterized by two longitudinal white stripes commencing 

 from the liead between the eyes and converging backwards to either 

 side of the dorsal fin. A diver jumped overboard and secured a 

 quantity of them in a bucket. Subsequent examination proved 

 them to be the fry of Plotosus, by reason of tlieir many-rayed ventral 

 fins and confluent second dorsal, caudal, and anal fins. 



At first I concluded from their habitat that they were the fry of 

 P. canius, but the proportions of the eyes and of the eight barbels 

 to the length of the head afterwards led me to assign them to 

 P. arab. 



Their size varied very slightly from about 18 to 19-5 mm. in 

 extreme length from the snout to the tip of the rounded tail fin. 

 Just in front of the origin of the anal fin and behind the vent there 

 is a pair of disc-like organs with sinuous margins. Between them 

 occurs the urogenital papilla. The character which would seem to 

 chnch their specific identification, namely, the total number of rays 

 in the conjoined vertical fins, was not available, inasmuch as the 

 anterior portion of the second dorsal fin membrane is destitute of rays 

 at this early stage. 



I do not know of any previous records of the pelagic swarming 

 habit of the fry of Plotosus. They formed, in the mass, a conspi- 

 cuous object, and might easily have been passed by as seaweed had 

 not curiosity prompted nearer acquaintance. Whether or not this 

 casual resemblance can really ajtford them an effective screen from 

 their enemies seems questionable. 



II. — LuLA Fry. 



The lula {Ophiocephalus striatus) is the most important fresh water 

 food fish of Ceylon, both as regards quality and quantity. It is also 

 known by its Hindustani name " murral," according to Mr. H. S. 

 Thomas's latest spelhng of the word, and by its Tamil name 

 " viral." The Hindustani name is the one most currently employed 

 outside Ceylon. 



It is what Dr. Day calls a compound breather, being more 

 essentially an air-breathing fish. The Ophiocephali "never obtain 

 oxygen for any length of time from the air in solution in the 

 surrounding water, but inspire it direct from the atmosphere, no 

 matter how cool and charged with air the water may be " ; and 

 they ' ' expire in a longer or shorter interval if unable to reach the 

 atmospheric air." They are thus independent of the state of the 

 water in which tli^y are living, and " in carrying live specimens 

 from the plains to the Nilgiri hills, this was most successfully 

 accomplished in water largely mixed with mud."* 



* Day, F. Report on the Fresh Water Fish and Fisheries of India and 

 Burma. Calcutta, 1873, p. 25. 



X 7(8)08 



