326 NEW-YORK FAUNA. 
THE HAIRY BALLOON-FISH. 
Diopon Piosus, 
PLATE LV. FIG. 180.— (CABINET OF THE LYCEUM.) 
The Hairy Diodon, Diodon pilosus. Mrrcuiut, Trans. Lit. and Phil. Soc. Vol. 1, p. 471, pl. 6, fig. 4. 
Diodon asper? Cuvier, Memoires du Museum d'Histoire Naturelle, Vol. 4, p. 138. 
D. pilosus. Ip. Régne Animal, Ed. anglaise, Vol. 10, p. 567. a 
Characteristics. Body with long flexible setaceous spines. Caudal pointed. Length two to 
four inches. 
Description. Body oblong, cuboidal. Every part of the surface, except a small space 
round the mouth and eyes, and another including the base of the caudal fin, furnished with 
bristles ; these are from two to four-tenths long, directed backwards, though probably capable 
of erection at the will of the animal. They are somewhat longer and more crowded on the 
dorsal and posterior parts of the body; they are all soft and flexible, suggesting the idea of 
hair-like processes. Eyes large and lateral; the space between the orbital margins depressed, 
concave. Nostrils single, with an obliquely truncated tubular orifice. Mouth terminal, 
broad, with thin membranous lips. Jaws, or rather the teeth, ending in an acute tip in front. 
Branchial orifice ear-shaped, placed in front of the upper part of the base of the pectorals. 
The dorsal slightly anterior to, but over the anal; rounded on its margin, higher than wide. 
Pectoral short and broad ; its upper rays longest. Anal fin broad, and similar in shape to the 
dorsal. Caudal lanceolate. 
Color. Brownish above ; ashy white beneath; the prickles of a metallic golden color. On 
the back and along the sides are several oblong, distant, blackish brown spots. 
_ Length, 2-0. 
Fin rays, D. 12); P. 20; A. 14; C. 9. 
This remarkable little species, which has been occasionally taken in the bay of New-York, 
was first described by Mitchill. It was subsequently referred by Cuvier (Op. sup. cit.) as 
the young of a species which he names asper, two feet and a half long. It is probable that 
his opinion underwent some modification subsequent to the publication of that paper; for in 
the last edition of his Régne Animal, D. pilosus is cited as a distinct species. 
