634 Mr. C. T. Hegan on the Anatomy and 



longer, its first uncovered segment simple and ratlier shorter 

 than either of the following two. 



Antennce with some very elongate hairs; basal joint twice 

 as long as broad, third obconical, narrower than the second 

 but nearly as long ; joints 4-7 differing but little, each 

 slightly longer than broad, the eighth rather shorter, the next 

 two transverse, the terminal conical, including its distinct 

 apical appendage. 



Underside nitid. Head rather thickly pubescent behind, 

 smooth and unimpressed near the hind angles, flat between 

 the eyes, but with slightly curved and distinctly tliickened 

 hind borders ; in front, behind the mentum, there is a 

 transverse fovea. Metasternum short, slightly impressed 

 behind the middle. Abdominal segments : third and fourth 

 nearly equal, largest ; fifth nearly as long, truncate beliind in 

 the middle; sixth broadly conical, flat, not reaching the 

 extremity but without any well-marked apical suture. 



Allied to S. laticeps (3362), but the whole insect is broader 

 and the head is less trigonal. In 3362 the hind angles are 

 directed slightly outwards ; in this species they are rounded, 

 and the sculpture underneath also differs. The elytra are 

 larger and less narrowed towards the base. 



Length 2f ; breadth | mm. 



Greymouth {Hehns). A single specimen from Dr. Sharp's 

 collection in the British Museum. 



Most of the pubescence has been rubbed off and most 

 likely the minute squamse on the first exposed dorsal 

 segment disappeared along with it. The real structure of 

 the terminal ventral segment is obscured by gum, but the 

 sculpture of the underside of the head denotes the male. In 

 any case, when placed side by side with S. laticeps it is seen 

 to be distinctly different from it. 



LXXVIII. — The Anatomy and Classification of the Teleostean 

 Fishes of the Order Discocephali *. By C. Tate Regan^ 

 M.A. 



(Published by permission of tlie Trustees of the British Museum.) 



The order Discocephali differs from the Percoids especially 

 in the remarkable transformation of the spinous dorsal fin 

 into a flat, oval, transversely laminated, adhesive disc, which 



* On the structure of the adhesive disc cf. Beck, ' Die Plaftscheibe der 

 ^cAe?ie/s rew!o;-«,' Schaffhauseu, 1879; and Storms, Ann. & Map. Nat. 

 Hist. (G) ii. 1888, p. 67. For a discussion of the systematic position of 

 the group cf. Gill, iu Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1898, 

 pp. 2265-2268. 



