Paul Arnold's painting of ARNThe Annals and magazine of natural history; zoology, botany, and geology - Ser: 8, V 2, P 29, 1908
II. — Descriptions of Two new Cyprinodontid Fishes from West Africa. By G. A. BOULENGER, F.R.S.
Depth of body 4 1/2 to 5 1/2 times in total length, length of head 3 to 3 1/2 times. Snout a little shorter than eye, the
diameter of which is 3 1/3 times in length of head; lower jaw projecting beyond upper; interorbital width 2/5 length of head. Dorsal 15-16, originating slightly in advance of anal, above tenth or eleventh scale of lateral line, and at equal distance from eye and from root of caudal; longest (posterior) ray quite as long as head in males, shorter in females. Anal
15-17, similar to dorsal. Pectoral about 2/3 length of head. Caudal rounded in females, with upper and lower rays produced in males. Caudal peduncle twice as long as deep. Scales 25-27 in longitudinal series, 20-22 round body; an interrupted series of lateral line pits. Pale olive, spotted or dotted with crimson on the head, body, and vertical fins. According to Mr. Arnold's coloured sketches, the male has a blackish band along the upper part of the dorsal and anal fins.
Total length 45 mm.
Several specimens were presented to the British Museum by Mr. J. P. Arnold, of Hamburg; this fish, which he kept
in his aquarium, formed part of an interesting series brought over alive from the mouths of the Niger. F. arnoldi
is allied to F. bivittatus
Loenb., and F. loennbergii, Blgr., but differs from both in the more numerous anal rays.