190 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 94 



SOVICHTHYS, new genus 



This remarkable new genus of Pimelodidae differs greatly from all 

 other members of that family, except Iheringichthys Eigenmann and 

 Norris, 1900, in lacking teeth on the premaxillaries, except in the 

 young. Sovichthys is remarkable in having about 14 to 17 minute 

 tubes in the skin, associated with tiny papillae or pores, extending at 

 right angles to the lateral line and mostly encircling the body. 



The Pimelodidae are usually defined as catfishes with nares widely 

 separated, remote from the orbits; four mental barbels and two 

 maxillary barbels; a well-developed adipose fin; gill membranes free 

 from isthmus; the skin without bony plates; teeth in villiform bands 

 on premaxillaries and dentaries. However, the description of the 

 character of the premaxillary teeth as usually understood must be 

 modified if Iheringichthys and Sovichthys are to remain in that family. 

 The premaxillaries are edentulous in the adults of both these genera 

 and in the half-grown of Sovichthys. On a specimen of Sovichthys at 

 a length of 32 mm. a very small patch of delicate villiform teeth was 

 found near the midline on each premaxillary, but at a length of 59 

 mm. the teeth were absent and a firm plate could be felt where the 

 teeth were to be expected. The teeth in a specimen of Iheringichthys 

 megalops (U.S.N.M. No. 52611), 134 mm. in standard length, were 

 well developed on the premaxillaries. In the adults of Sovichthys the 

 premaxillaries are thickly covered with the skin and tissues of the 

 upper lip and each dentary has a narrow band of delicate villiform 

 teeth. 



The supraoccipital process has a wide base, then tapers backward 

 and meets the predorsal plate; the first simple ray of the dorsal is not 

 spinous but articulated and is longer than the first branched ray; 

 pectoral spines not locking open; the first ray of the pectoral fin is 

 distinctly a spine, the front margin near tip with small teeth pointing 

 basally, and with posterior edge of this spine having numerous sharp 

 teeth pointing toward base of spine, in adults the anterior margin of 

 the spine being rough; frontal fontanel present but narrow; occipital 

 fontanel narrow, its anterior end beginning opposite rear margin of 

 orbits; no postcleithral process from pectoral girdle behind and above 

 base of pectoral; snout produced, mouth inferior; margin of eye free; 

 gill membranes free from the istlmius, extending forward, joined in 

 midline anteriorly; in front of this juncture is a pouch that extends 

 to under inner pair of mental barbels; another pouch occurs between 

 upper lip and base of maxillary barbel that extends nearly to midline 

 under upper lip, separated from its fellow on opposite side by a mem- 

 branous partition; interorbital space flat; air bladder well developed 

 and in contact with skin behind pectoral girdle; inside of gill cavity, 

 below orbit, are three folds of tissue; along front of gill arches at base 



