8 R. E. LlOVD : The Fauna of the Arabian Sea. [VOL. I, 



DESCRIPTIONS OF NEW SPECIES. 



Fish. 

 Pcristethus a dent, sp. nov. 

 Br.r. 7 | a.D. 7 | p.D. 14 | v. 5 | P. 12 2 j L.L. 24 j L.tr. 4 | A. 14 



The length of the prseorbital process is equal to one-third of the 

 distance between its extremity and the anterior border of the 

 orbit. The prseocular ridge has a prominent, finely serrated border ; 

 it ends behind in a sharp spine, which is nearly as long as the 

 eye. The inner borders of the prseorbital processes are parallel, 

 their outer borders, if prolonged, would meet in front at an angle 

 of 40°. The prseorbital processes therefore appear to converge. 

 The length of each labial tentacle is equal to the width of the 

 mouth. 



The osseous plates between the ventral fins are unusually 

 thick. The greatest length of each anterior ventral plate is equal 

 to the greatest breadth of both combined. The greatest length 

 of the posterior ventral plates is half that of the anterior ones. 

 The greatest length, in both cases, is to one side of the middle line. 

 A quadrangular portion of the posterior plates fits into a correspond- 

 ing hiatus in the anterior plates. Throughout the length of the 

 body, on either side, there are four rows of plates, each with a 

 large spine shaped somewhat like a rose- thorn, their points curving 

 backwards. The lowest row is much less conspicuous than the 

 others. 



There are large postorbital, occipital, post-temporal, and two 

 opercular spines, a small upper and a large lower one, on either 

 side. There is one small median spine, an orbit's length in front 

 of the orbits. 



The greatest height is one-fifth the total length. Total length 

 of the single specimen 6^ inches : greatest length of the head three 

 inches. 



Colour — Reddish yellow ; pectorals grey ; dorsals tipped with 

 black. 



Habitat — Gulf of Aden ; 130 fathoms. 



Narcine mollis, sp. nov. 



The vent is slightly nearer the anterior margin of the snout 

 than the tip of the tail. The disc is evenly rounded, it is slightly 

 broader than long. The margin of the flap formed by the confluent 

 nasal valves is most prominent at the sides, unlike N. tivilei, the 

 other Indian species. The whole quadrangular space which lies 

 between the two nasal clefts is nearly as long as it is broad. In 

 N. timlei this space is three times as broad as it is long. 



The anterior dorsal is slightly smaller than the posterior ; 

 it commences just behind the ventrals. The dorsal and caudal 

 fins have blunt pointed ends and the folds of skin along the sides 



