458 PHTSOSTOMI. 



B. Olohular teeth on the palate. 



13. Arius Btichanani, A. 22. Head 4f in the total length. Eye, 7 to Si in tte length of head. The 

 maxillary barbels reach the first third of the pectoral spine. Teeth on the palate in two oval patches placed far 

 back. Dorsal spine as long as the head behind the angle of the month. Hooghly and Burmese rivers. 



14. Arms falmrius, A. 18-20. Head 4 to 6 in the total length. Eye, 6i to 6 in the length of head. 

 The maxillary barbels reach end of head. Teeth on palate in two semi- triangular patches, parallel along the 

 median line. Dorsal spine as long as the head excluding the snout. Seas and estuaries of India to China. 



15. Arius Malabaricus, A. 20. Head 4^ in the total length. Eye, 6^ in the length of head. Gape of 

 mouth 2/5 of length of head. The maxiUary barbels as long as the head. Teeth on palate in two oval patches 

 weU forwards and slightly convergent anteriorly. Dorsal spine as long as the head behind the angle of the 

 mouth. Canara. 



16. Arius platystomus, A. 19. Head 4 in the total. Eye, 7 in length of head. Width of gape of mouth 

 4/7 of the length of head. Maxillary barbels reach just beyond base of the pectoral. Teeth on palate in a 

 pyriform band, placed well forward, slightly converging anteriorly. Dorsal spine as long as the head excluding 

 the snout. Canara. 



17. Ariiis nella, A. 19. Eyes small, in front half of head. Coromandel coast of India. 



18. Arini.s macronotacanthus, A. 18-19. Head 4 to 4^ in the total. Eye, 5i to 6 in the length of head. 

 Maxillary barbels reach middle of pectoral spine. Teeth on palate in a p^yriform band, placed well forwards, 

 and widely divergent posteriorly. Dorsal spine as long as the head behind the nostrils. India to the Malay 

 Archipelago. 



19. Arius gagora, A. 18. Head 4 to 4^ in the total length. Eye, 7 to 8 in the length of head. 

 Maxillary .barbels not quite so long as head. Teeth on palate in a large semi-ovate patch on either side nearly 

 parallel with one another. Dorsal spine as long as the post-orbital portion of the head. Seas and estuaries of 

 Orissa and Bengal to Siam. 



20. Arius jatius, A. 18. Head 4i in the total length. Eye, 4i to 5 in the length of head. Maxillary 

 barbels shorter than the head. Teeth in a small ovate patch posteriorly on either side or else absent. , Dorsal 

 spine as long as head excluding the snout. Estuaries and rivers, of Bengal and Burma. 



21. Ari^ts tenuispinis, A. 18. Head 3^ in the total. Eye, 7 in the length of head. Maxillary barbels as 

 long as the head. Teeth on palate absent (?two pear-shaped globular patches normally). Bombay, ? Ceylon. - 



22. Arius jella, A. 17-18. Head 4| in the total. Eye, 6 in the length of head. Maxillary barbels 

 nearly as long as the head. Teeth on palate in two convex, oblong, ovate, patches rather convergent behind. 

 Dorsal spine as long as the head excluding the snout. 



23. Arius Bussumieri, A. 14-16. Head 4 to 4-^ in the total. Eye, 6^ in the length of the head. 

 Maxillary barbels rather longer than the head. Teeth on the palate in two patches on either side. Dorsal spine 

 as long as the head excluding the snout. Malabar and Ceylon. 



A. Villiform teeth on the palate. 

 1. Arius Burmanicus, Plate CV, fig. 4. 

 Day, Proc. Zool. Soc. 1869, p. 618. 

 Nga-young, Burmese. 



B. vi, D. i/O, P. 1/10, V. 6, A. 19-22 (yf-.f^), C. 15. 



Length of head 3^ to 3|, of caudal 5, height of body 7 in the total length. Eyes — without free orbital 

 edges, diameter 7 to 8| in the length of head, 2^ to 3 diameters from the end of snout, and 1\ to 2 apart. Head 

 depressed, snout spatulate, upper jaw the longer, the greatest width of head equals 2/5 of its length, whilst its 

 height is less. The median longitudinal groove on the head narrow and does not extend so far as to the base of 

 the occipital process which is keeled and rather wider at its base than it is long, whilst superiorly it reaches a 

 V-shaped basal bone. Upper surface of the head with roughened lines which are closest together at the 

 posterior end of the median groove and on the occipital process. Barhels — short, the maxillary do not quite 

 reach the base of the pectoral fin, the outer mandibular are nearly as long. Teeth — those on the palate villiform 

 in two small, oval, obliquely set, patches (not as large as the eye) and diverging posteriorly. Fins — the dorsal 

 one-half higher than the body, its spine strong, half as long as the head, and serrated anteriorly and posteriorly : 

 base of adipose dorsal about as long as that of the rayed fin. Pectoral spine of equal length, stronger, serrated 

 on both edges. Ventral nearly reaches the anal. Colours — purplish, dashed with copper, becoming dull white 

 on the sides and beneath. Both dorsal fins externally stained with black. 



In external appearance this fish strongly resembles Macrones aor. 



Habitat— Tidal rivers of Burma as at Bassein and Moulmein. The specimen figured (from Moulmein) is 

 9 inches in length. It attains at least a foot. 



2. Arius nenga, Plate CIV, fig. 3. 



Pimelodus nenga, Ham. Buch. Fish. Ganges, pp. 171, 376. 



Pimelodus auratus, Ham. Buch. MSS. figure. 



Bagrus arioides, Cuv. and Val. xiv. p. 440. 



Arius nenga, Bleeker, Beng. en Hind, p. 56. 



Arius arioides, Bleeker, Beng. en Hind. p. 56; Blyth. Proc. As. Soc. of Beng. 1858, p. 286; Gunther, 

 Catal. V, p. 143. ^ ' r > 



