1919. ] N. ANNANDALE: Fish from India and Persia. 67 
1. Pectoral fins hardly longer than head, not nearly reaching 
ventrals rs Sie = ... D. nasutus. 
2. Pectorals distinctly longer than head, nearly reaching ven- 
trals ee oe A .... D. macrochir. 
SECTION I.—Gyroup of Discognathus variabilis. 
1863. Discognathus (s.s.), Bleeker, Atl. Ichth. II], p. 24. 
In this group the adhesive apparatus on the ventral surface 
of the head is comparatively little differentiated, the snout projects 
little beyond it, and the general facies of the fish is less peculiar, the 
ventral surface being less flattened and the caudal peduncle more dis- 
tinct. As Boulenger has pointed out in discussing an African 
species (D. quadrimaculatus ') belonging to the group, it has a close 
resemblance to the eastern Asiatic genus Crossochilus, a genus 
which, according to most recent authors, is not found west or 
north of the Malay Peninsula; but there is a distinct difference in 
the structure of the mouth and in particular of the lower lip.» In 
this section of Discognathus, as also in the other species, the jaws 
are much less sharp than in Crossochtlus and are never horny or 
bony, but always cartilaginous and covered with a thin epithelium. 
The upper lip is joined to the lower lip directly by a frenulum, but 
the lower lip itself is vestigial, disappearing entirely in most 
species in the middle of the jaw, though in some, as in D, phryne, 
it is represented by a delicate fold of integument that may be ex- 
tended over the whole jaw. The transverse band of tissue which 
stretches in many species across the anterior margin of the mental 
disk just behind the lower jaw appears to be quite distinct, as is 
shown by the condition in D. phryne, from the lower lip. It is 
this band of tissue, however, which is labelled /.J. in my figure on 
p. 114, Rec. Ind. Mus., Vol. XVI. The snout does not appear to 
be produced or tuberculate in any of these species. 
It is possible that Discognathus is derived from Crossochilus 
and that the species of the first section are closely related gene- 
tically to that genus. The geographical difficulty is not so great 
as might appear at first sight, for the species Cirrhina latia is 
closely related to Cyrossochilus, in which indeed it is placed by 
Giinther* and Vinciguerra,* and the range of Cirrhina latia ex- 
tends from Upper Burma to Baluchistan. 
The eponymous species of this group is found in Palestine and 
Mesopotamia. The three discussed here occur in the extreme east 
of Persia or on the North West Frontier of India, while D. quadri- 
maculatus is recorded from various lakes and rivers in the upper 
watershed of the Nile and D. vinciguerrae (which, so far as I can 
judge from Boulenger’s figure,> also belongs to the group) from 
5 Boulenger, Fish. Nile, p. 185, pl. xxxi, fig. 4 (1907), and Cat. Fresh-w. 
Fish. Africa \, p. 347, fig. 261 (1909). 
