29. SILURID^E PILODICTIS. 101 



front, slightly rough or nearly entire behind ; its length 3 times in dis- 

 tance from snout to dorsal. Anal rays about 16. Humeral process 

 very short and sharp. Size very large; reaches a length of more than 



a foot. Vermont to Virginia, Nebraska, and Texas ; rather common. 



(Eafinesqnu, Amer. Mouth. Mag. 1818, 41 ; Giintlier, v, 101 ; Jordan, 1. c. 99 : Nota- 

 ni* occidcntaUs Gill, Proc. Bost. Soc. Nat. Hist. 1852, 45 : Noturus platycuphalus Giin- 

 tlier, v, 104.) 



53. PILODICTIS Rafiuesque. 



Mud Cats. 

 (Opladelus Eaf. 1820.) 



(Bafineaqne, Prodrome de soixante-dix nouveaux genres, etc., Journ. Phjs. Paris, 1819, 

 422 : type Pilodictis liinosus Eaf. = Silurus olivaris Eaf.) 



Body much elongated, very slender, much depressed, anteriorly 

 broader than high. Head large, very wide and depressed, latterly 

 expanded, above broadly ovate, and in profile cuneiform. Skin very 

 thick, entirely concealing the skull. Supraoccipital bone entirely free 

 from the head of the second iuterspinal. Eyes small. Mouth very 

 large, anterior and transverse. The lower jaw always projects beyond 

 the upper. Teeth in broad villiform bands on the intermaxillaries and 

 dentaries. The iuteroiaxillary band is convex anteriorly, and proceeds 

 to the insertion of the maxillaries, where it is abruptly angularly de- 

 flected, and proceeds backward as an elongated triangular extension. 

 The band at the symphysis is slightly divided, and anteriorly separated 

 by a small triangular extension of the labial membrane. The lower 

 band of teeth is anteriorly semicircular and attenuated to the corners of 

 the mouth. There are about 12 branchiostegal rays on each side. The 

 dorsal fin is situated over the posterior half of the interval between the 

 pectorals and ventrals, and has a spine and about 7 branched rays. 

 The spine is rather small, and more or less enveloped in the thick skin. 

 The adipose fin is large, and has an elongated base resting over the pos- 

 terior half of the anal ; it is very obese and inclines rapidly backward ; 

 it is rather less free posteriorly than in Amiurus. The anal fin is small ; 

 it commences far behind the anus, is a little longer than high, and is 

 composed of about 13 rays. The caudal fin is oblong, subtruncated, 

 placed on a vertical basis, and with numerous accessory simple rays, 

 recurrent above and beneath the caudal peduncle. The pectorals have 

 a broad compressed spine, serrated or dentated on its external and in- 

 ternal margins, and with a prolonged fleshy integument obliquely 

 striated. The ventrals are rounded and have 9 rays, 1 simple and 8 

 branched. One species known, (-s/o?, mud; ty^us, fish.) 



