TERTIARY FISHES. 
11—251 
whole of India, and its range therefore covers the area inhabited by its fossil pro- 
genitor. 
Genus III. RITA, Bleeker.^ 
Characters. — Teeth on the palate granular or molariforui ; the upper jaw longer 
than the lower ; posterior border of the supraoccipital process notched to receive the 
basal bone of the dorsal spine (pi. XXXVII. fig. 6); upper cranial bones covered 
with a granular or subradiate sculpture. 
Distribution. — The genus is confined to the Oriental region; five species being 
recorded in Gunther’s “ Catalogue of Fishes,”^ and a sixth having been subsequently 
described by Dr. Anderson^ under the name of B. sacerdotum. 
Species. Rita geandiscutata, n. sp. nohis. 
(From the Siwaliks.) 
History. — No previous description has been given of the specimen on which this 
species is founded. 
Basal hone of dorsal spine,— Fho, specimen represented of half the natural size in 
plate XXXVII. fig. 3 was collected by Mr. Wynne in the Siwaliks of the Punjab ; 
and consists of the entire basal bone of the dorsal spine of a gigantic siluroid. 
Compared with existing siluroids this specimen agrees more nearly with the corres- 
ponding element in Rita than in any other genus, and in order to exhibit this 
resemblance the hinder part of the cranium and basal bone of the dorsal spine of a 
young individual of the existing Indian R. crucigera^ (Owen) has been drawn in fig. 
6 of the sanle plate. If the two figures be compared it will be seen that in the 
contour of the posterior border the fossil agrees almost precisely with the recent 
bone, the facettes marked e being exactly similar; the anterior extremity of the two 
is also constructed on the same plan, although the processes (/) for articulation with 
the supraoccipital process are more developed in the fossil. On the lateral borders the 
fossil differs by its expansion into the strongly marked processes c and c?, which are 
totally wanting in the recent bone ; but it is probably that this is not more than a 
specific variation. In the extreme prominence of the upper half of the middle line 
the fossil also differs very markedly from the recent specimen, and its sculpture also 
appears relatively finer. 
Afinities. — That the fossil specimen indicates a siluroid specifically distinct from 
Rita crucigera (which attains a length of four feet) is perfectly evident ; and its 
specific distinctioq, from the four smaller species mentioned in Gunther’s “Catalogue” 
is equally clear. As Rita sacerdotum y'whioh attains a length of five feet, appears to 
be less close to the Siwalk specimen than R. crucigera., the specific distinctness of the 
fossil form may be assumed ; and since it is probable that the differences distin- 
guishing the latter from the existing species of Rita are not of more than specific 
1 “ Iclithyol. Archipel. Ind. Prodromus— Siluroidei,” p. 60 (1858). 2 Vol. V. pp. 92-94 (1864). 
3 “ Eesults of Yunnan Expedition,” p. 864, pi. LXXIX. fig 3 (1878). 
i Day (“ Fishes of India ”) adopts the name R. biichanani for this species. 
