PORODERMA. 69 



edge of caudal without special armature 



Apristurus (page 96) 

 anal and subcaudal elongate; only one dorsal fin 



Pentanchiis (page 95) 

 posterior nasal valve absent, anterior reaching mouth 

 anal and subcaudal short, dorsals larger 



snout short, narrow; a fold below the eye 



Atelomyderus (page 100) 

 anal and subcaudal short, anal larger than dorsals 

 snout short, depressed; no fold below the eye 



Haploblepharus (page 101) 

 Origin of first dorsal slightly in advance of ventral origins 

 labial folds short, upper longer 



anal long, distant from the subcaudal 



snout elongate . . . . Proscyllium (page 102) 



PoRODERMA. 



Poroderma A. Smith, 1837, Proc. Zool. soc. Lond., p. 85. 



Body rather stout, cavity more than half the total length. Head less than 

 one fourth of the total; snout short, longer than the mouth, depressed, blunt. 

 Nostrils without a nasoral groove; anterior valves short, widely separated, not 

 reaching the mouth, with a strong cirrus; posterior valves broad, short. Eyes 

 small; lower lid with a very slight fold. Mouth wide, short; teeth small, tri- 

 cuspid. Labial folds at the angles of the mouth, on the lower jaws only. Spir- 

 acles moderate, behind the eyes, not distant. Ventrals short. Scales small, 

 tricuspid, median cusp elongate, acute. First dorsal fin behind the ventrals; 

 second dorsal smaller than either first or anal. Gill openings medium, hindmost 

 above the pectoral, narrow. 



OfT the coasts of southern Africa. 



The species are distinguished almost entirely by differences in their mark- 

 ings; they are separated as follows: 



Marked by longitudinal stripes, nearly or quite unspotted 



nasal cirrus usually not reaching the edge of the lip . africanum (page 70) 

 Marked by spots, rings or vermiculations, spots sometimes confluent 



nasal cirrus longer, reaching the edge of the lip or beyond 



pantherinum (page 70) 



