igS Records of the Indian Museum. [Vol. XXII, 



was pointed out that this character did not seem to me of either 

 specific or generic value. The genus Afua is distinguished from 

 Acanthophthalmns by the absence of the ventral fins. Vinciguerra 

 does not recognise the genus Afua. but in doing so he does not 

 assign any valid reasons. According to him " le ventrali fossero 

 mancfnti per pura accidentalita o che per la lore estrema piccolezza 

 sieno sfuggite all' osservazione di entrambi questi naturalisti." I 

 have examined the two type-specimens (No. F --"/--) of A. fusca, 

 Btyth, but can find no trace of the ventrals in them; and cannot, 

 therefore, agree with Vinciguerra when he says that the ventrals 

 must either have been overlooked or accidentally broken in the 

 unique type-specimens of the genus. I look upon these cases as 

 abnormalities, though it is surprising that both the specimens 

 should have lost the ventrals. I have already referred to an 

 abnormal specimen of Barilitis dogarsinghi in which the ventral fin 

 of the left side is absent. I have also examined a specimen of 

 Rita rita, in the collection of the Government College Museum, 

 Lahore, in which the pectoral fin of one side is absent. In view 

 of what I have stated above I do not regard Aptia as a distinct 

 genus. 



There is another interesting observation which might be 

 referred to in this connection. After a careful examination of a 

 large collection of A. pangia from iManipur, I am of the opinion 

 that the form hitherto known as Apua fusca is only a hill- 

 stream phase of A. pangia. Vinciguerra distinguishes .4. pangia 

 from A. fusca, by the greater depth of its body, by the ventrals 

 being placed midway between the base of the caudal and the 

 middle or the posterior margin of the orbit, and by the position of 

 the dorsal, which in A. fusca ends just above the origin of the anal 

 fin. I have not been able to verify the above characters in the 

 case of the type-specimens of A. fusca. In these specimens the 

 dorsal fin is in advance of the anal, and its origin is not equidis- 

 tant from the base of the pectoral and the end of the caudal fin. 

 It arises in the posterior \ of the body. 



The specimens from the hill-streams like Sikmai, Amambi, 

 Phaidinga, etc., are slender, elongated and less deep, while those 

 from the muddy streams are stouter and deeper. The muddy 

 stream forms possess a soft dorsal fin like that of the genus 

 Adiposia.^ 



The structure of the soft dorsal fin of A. pangia is very 

 simple. The wall consists of a thin laj^er of epithelium and of a 

 muscular layer internal to it. There are no specialized gland-cells 

 and the muscular sheath consists of fine fibrils running transverse- 

 ly. The inner core consists of a highly vacuolated tissue, supplied 

 with a few blood vessels which lie in the middle. The muscles do 

 not run across the dorsal muscles but are continued along the body- 

 wall. 



' .\nnandale and Hora. Rec. Ind. Mus. .Will,, \i\). i8,^, — 186 (1920). 



