1901.] NATURAL SCIENCES OF FHILADELPHIA. 329 



referring it lo the above species. It has about 5G muscular bauds 

 between the posterior gill-opening and the anus. 



SCYLLIORHINID^. 

 2. Pristiurus melastomus (Rafines<iue). 



Galeus UTelastomus Rafinesque, Caratt. Anim. Sicil., 1810, p. 13. 



Nos. 566 to 574. Types of Scyll'mm melanostomum Bonaparte, 

 Fauna Italica, Pesci, Tomo III, vii, 1834, 89, PI. 131, fig. 3 

 (two figures). Italy. Bonaparte Coll. (No. 253). Dr. T. B. 

 Wilson. 



Mouth. — Moderately large, somewhat spacious and compressed. 

 The jaws aloue are furnished with teeth. Tongue a little free in 

 front, broad and flat, though somewhat rounded anteriorly. The 

 inside of the mouth is lined with smooth integument altogether 

 destitute of shagreen. 



Pharynx. — Spacious, elongate and compressed. Upon the walls 

 of the branchial arches are patches of fine shagreen, otherwise the 

 rest of the integument lining this region is perfectly smooth. 

 There are 5 gill-openings within the pharynx, which lead into as 

 many gill-pouches, and finally communicate externally by as many 

 gill- slits. Of the internal gill-openings, which are greater than 

 those which are external, the anterior is the largest, and they all 

 gradually diminish in length until the last, which is not more 

 than ^ the length of the first. The gill- pouches contain the gill- 

 filaments, and they are separated from each other by means of 

 inter-branchial septa. The gill-filaments are distributed in each 

 gill-pouch, so as to appear continuous, except in the last, where 

 they are only upon the anterior walls. They are of moderate 

 number, compressed, and adnate, except distally, to the walls of 

 the gill- pouches. There is a well-developed spiracle aperture 

 within the pharynx, anterior and superior to the first gill-opening. 

 It is furnished with pseudobranchiss. 



CEsophar/ns. — Short and somewhat constricted. The walls more 

 or less plicate. 



Stomach. — Spacious and bulky, and the walls greatly plicated, 

 except in the pyloric region. The tissues of this division of the 

 enteric canal are thicker than any other. 



Intestine. — The duodenum is very short, existing as a simple 

 tube greaiy constricted, until the presence of the colon is indicated 



