4(10 PHrSOSTOMI, 



on the palate likewise Tilliform in two somewliat oWiquely oval patches diverging anteriorly. F'nis — dorsal spine 

 rather strong, half as long as the head and serrated on both sides : the length of the base of the adipose fin 

 equals 2/3 of the length of that of the rayed fin. Pectoral spine of about the same length as that 

 of the dorsal and seri-ated on both edges, the fin reaches 2/3 of the distance to the ventral, whilst the latter 

 does not extend to the anal. Colours — upper portion of rayed and also of 2/3 of adipose dorsal black : 

 pectoral, ventral, and anal stained gray. 



Ilahitat. — The Salwein river at Moulmein in Burma. It attains a foot or more in length. 



5. Arius Sumatranus, Plate CVII, fig. G. 



Bagrus Sumatranus, Bennett, Life of Sir S. Raflles, p. G91. 

 Arius SiMnatranus, Giinther, Catal. v, p. 162. 



B.'vi, D. i 1 0, P. 1/10, V. 6, A. 18-19 (t35t*)> C. 17. 



Length of head 4y to 4^,' of caudal .5i, height of body 5^ in the total length. Etjes — diameters 

 5 in the length of head, If diameters from the end of snout, and 2 apart. The greatest width of the head 

 exceeds its height and equals its length behind the angle of the mouth. Upper surface of the head with 

 scattered granulations, which are more lineated on the occipital process. Median longitudinal groove 

 becomes narrow posteriorly, nearly reaching the base of the occipital process, its edges in the last portion of its 

 extent are raised. Occipital process slightly keeled, as broad at its base as it is long : basal-bone crescent 

 shaped and narrow. ISnrheh — the maxOlary ones reach end of the head, the outer mandibular ones 

 the base of the pectoral tin. Teeth — in palate villifonn, in two triangular patches diverging posteriorly. 

 Fins — dorsal spine as long as the head behind the angle of the mouth, and serrated on both edges : base of 

 adipose dorsal 2/3 of that of the rayed fin. Pectoral spine as long as the head excluding the snout, externally 

 it is roughened in its lower, serrated in its upper portion, internally it is denticulated, it does not 

 reach the ventral. Ventral reaches 2/3 of the way to the anal. Cohmrs — bluish-green superiorly, becoming 

 lighter on the sides and beneath : edges of fins stained gray, very little black on adipose dorsal. 



This fish is closely allied to A. venosus, but has a longer head, &c. 



In the type specimen, which is in a very bad state, the cubito-humeral process is larger than in my 

 specimen, and the summit of the head is more granulated, and the palatine group of teeth is divided. 



Habitat. — Andamans to the ilalay Archipelago. 



6. Arius venosus, Plate CVI, fig. 2. 



Cuv. and Val. xv, p. C9 ; Bleeker, Silur. Batav. j). 39, and Atl. Ich. Silur. p. 33, t. 54, f. 1 ; Gunther, 

 Catal. V, p. 159. 



Arius Iceviceps, micruropterygius, manjoiig, and micronotacantlius, Bleeker, Silur. Batav. pp. 3G, 38. 

 Cephalocassis venosus, Bleeker, Prod. Silur. p. 113. 



B. vi, D. i I 0, P. 1/10, V. 6, A. 18-19 (Vf ), C. 17. 



Length of head 5^, of caudal 5, height of body 6 in the total length. Eyes — diameters 4j in the length 

 of head, 1^ diameters from the end of snout, and 2 apart. Snout rather obtuse, and the upper jaw 

 the longer : the width of the gape of the mouth equals 1/2 the length of the head. The greatest width of 

 the head equals its length excluding the snout, and slightly exceeds its height. Upper sui-face of the 

 head with scattered granulations, which are more nvimerous on the occipital process. Median longitudmal 

 groove on the head shallow except in its posterior portion, which is narrow and deep as far as the base of the 

 occipital process which is keeled, and as broad at its base as it is long. Basal bone V-shaped, and laterally 

 narrow. Barbels — the maxillary ones extend to the base of the pectoral fin, the outer mandiliular one.s 

 are shorter. Teeth — villiform on the palate, in two triangular patches, the points of which are directed 

 backwards, the patches are about as large as the eye, as broad as long, and rather approximating anteriorly. 

 Fins — the dorsal as high as the body, its spine rather strong and as long as the head behind the angle 

 of the mouth, anteriorly it is serrated in its upper, granulated in its lower half, posteriorly it is serrated : 

 base of adipose dorsal equals half that of the rayed fin. Pectoral spine as long as that of the dorsal, 

 granulated and serrated externally, denticulated internally. The ventral reaches the anal : upper caudal lobe 

 the longer. 



This species differs from A. Sumatranus, more especially in having a comparatively much shorter head. 



Habitat. — From Burma to the Malay Archipelago. The specimen figured was from the Nicobars. 



7. Arius parvipinnis, Plate CXIII, fig. 1. 



Silurus, Russell, ii, p. 52, and Chiiita jellah, pi. 1G7. 



.'' Bagrus chinta, Cuv. and Val. xiv, p. 445. 



? Arius chinta, Bleeker, Beng. en Hind. p. 56. 



B. vi, D. H 0, P. 1/10, V. 6, A. 19 (J), C. 18. 



Length of head 4f, of caudal 4j-, height of body 6 in the total length. Ei/es — in anterior half 

 of the head, diameters 6j in the length of head. If diameters from the end of snout, and 3 apart. Greatest 

 ■width of the head equals its length behind the nostrils, and exceeds its height by 1/4. Upper jaw somewhat 



