456 phtsostom:i. 



B. Teeth m loth jaws, villiform or cardiform. 

 1, Rita hastata, Plate GUI, fig. 4. 

 Arlus hastatus, Val. in Jacq. Voy. Ind. Ori. Atl. Poiss. pi. 18, f. 2 ; Cav. and Val. xv, p. 97. 

 Arms pumilus, Yal. 1. c. f. 1 (yoimg) . 



Phraaiooephalus hutumee, Sykes, Trans. Z. S. ii, p. 372, t. 65, f. 3. 

 Bagrus ? hutwrnee, Jerdon, M. J. L. and Sc. 1849, p. 340. 

 Rita hastata, Giintlier, Catal. v, p. 93. 

 'Hxta hutwrnee, Giinther, Catal. v, p. 93. 



B. viii, D. i I 0, P. 1/10, V. 7-8, A. 13-14 (-j-?^), C. 17. 



Length of head 4| to 4|, of caudal 5 to 6, height of body 6 in the total length. %es— covered with 

 skia. TJupU oval, diameters 4^ to 6 in the length of head, 1| diameters from the end of snout, and 1 apart. 

 Greatest width of the head equals its length behind the angle of the mouth: upper jaw the longer: 

 the width of the mouth 3/8 of the length of the head. Upper surface of the head (except just anterior to the 

 occipital process) covered with skin, the portion in front of the occipital process and the process itself 

 with roughened lines, the latter half longer than wide at its base, anteriorly emarginate to receive the basal 

 bone of the dorsal fin. Scapular process rough but not elongated. Oubito-humeral process as long as the head, 

 sharply pointed posteriorly, and rugose in lines. Barbels — the maxillary reach the base of the pectoral 

 fin, the mandibular to below the hind edge of the eye : the nasal ones short. ' Teeth — in villiform or cardiform 

 rows in both jaws : ia two elliptical patches on the palate, converging anteriorly, and widely asunder along the 

 median line, they consist of pointed ones anteriorly and more granular ones behind. Fins — dorsal spine of 

 moderate strength, as long as, or even longer than, the head, finely serrated posteriorly in its upper portion, 

 and also anteriorly along its lower third : length of the base of the adipose dorsal 2/3 of . that of the rayed fin : 

 pectoral spine stronger and a little longer than that of the dorsal, denticulated on both edges : caudal 

 forked. Colours — brownish along the baek, silvery on the sides. 



The type specimen of A. hastatus, Val. is about 4^ inches in length and may have come from Poona 

 where it is common, it has villiform teeth in the jaws. 



Habitat. — Deccan, Poona, Tamboodra and Kistna rivers. 



Genus, 5 — Akitts, Giwier and Valenciennes. 



Sciades, sp. and Ariodes, Miill. and Trosch. : Mexanematichthys, Chdritinga, Hemiari/us, Cephaloeassis, 

 Netwma and Pseudariios, Bleeker. 



Branchiostegals from five to six. Qill-merribranes not confluent with the shin of the isthmus, and scarcely, or 

 not notched. Head osseous superiorly, or covered with very thin shin. Eyes with free orbital margins. Mouth 

 anterior : -upper jaw generally the longer. Anterior and posterior nostrils placed close together, the latter being 

 provided with a valve. Barbels six, one maxillary, a/nd two mandibular pairs. Teeth in the jams villiform : there 

 are nearly* always palatine, and sometimes vomerine ones, these may be villiform or granular. First dorsal with 

 one spine and seven rays if the adipose of moderate length or slwrt : pectoral spine strong wnd serrated ; ventral with 

 six rays, situated behind the vertical from the posterior margin of the rayed dorsal fm : caudal forked or emarginate. 

 An axilla/ry pore. Air-vessel not enclosed in bone. 



GonsiderabLe stress has been laid in this genus upon the character of the teeth, and whether they are 



viUiform or granular forms a good method of division. Further sub- divisions, as whether the groups are 



continuous or not so, appear nnadvisable, because in some species the size of the patches of palatine teeth 



- increase with age, thus altering their original conformation, and causing one patch to impinge on its 



neighbour. 



There is likewise another question as regards the palatine teeth in these fishes, in Ariusjatius there are 

 usually two small patches of palatine teeth widely separated along the median line : but in some specimens 

 such are entirely absent as stated by Hamilton Buchanan, and subsequently denied by others. The 

 specimen figured has no trace of palatine teeth. Arius termispinis appears to me to be so similar to A. Layardi, 

 Giinther, excepting in having no palatine teeth, that I cannot help thinking they are identical, but have no 

 series to confirm or disprove this supposition. Gonsequently genus Hemipimelodus,X Bleeker, has its 

 representatives in India, but such are either abnormal specimens in which the palatine teeth were absent from 

 birth, or else have become lost due to age. These species would appear to be such as have globular teeth. 



The air-yessel is not enclosed in bone, is large, heatt- shaped, and internally subdivided into five chambers, 

 which communicate together anteriorly, the front one which is the largest occupies its anterior portion, behind 

 it a niedian septum divides it down the centre, and lateral partitions subdivide the posterior chambers into four, 

 (see A. gagora, p. 465.) 



^^^ ^^^^T^g of these fishes is peculiar and deserves attention, the eggs of Arius are large, averaging 

 about 0-5 to 0-6 of an inch in diameter and I found many males, also of Osteogeniosus, with from 15 to 20 of them 



* Species destitute of palatine teeth belong to genus Eemipimelodm, Bleeker. 



T Six in some Sonth American species accoiding to Valenciennes. 



t Dr. Giimher observes, « In species which have rudimentary vomerine teeth, these are sometimes entirely lost with age." 



