44 BERYCIDJi:. 



streaK ; snout and fins red ; the spinous dorsal violet, with rose- 

 coloured streaks. 

 Amboyna. 



a. Adult. Amboyna. From Mr. Frank's Collection. 



b. Half-grown. Amboyna. From Mr. Frank's Collection. 



c. Adult : skeleton; Amboyna. From Mr. Frank's CoUection. 



d. Adult. AmbojTia. From Mr. Stevens's Collection. 



Sheleton. — The general structure of the skull is very similar 

 to that of H. ruhrum, but with such modifications as to indicate the 

 specific difference as well as the external characters do. The nan-ow 

 intersj)ace between the eyes is still more conspicuous in the skeleton. 

 The groove for the posterior processes of the intermaxillary bones 

 is very like that of H. ruhrum, and extends between the i)rincipal 

 frontals, but scorcely beyond the level of the anterior margin of the 

 orbit. The fan-hke expansion on the vertex is formed by seven or 

 eight radiating branches. 



The maxillary bone is styliform at its origin only, and soon becomes 

 broader, forming a triangular plate with the posterior edge rather 

 concave and the anterior convex : the supplementarj^ bone is un- 

 usually developed, forming nearly one-half of the outer part of the 

 maxillary; it is crescent-shaped, Avith a small os intercalare at its 

 upper extremity ; it is roughened by streaks, the maxillary itself 

 being smooth. The intermaxillaries are separated from one another 

 by a smaU notch ; they are |^ as long as the maxiUaries, and have 

 posteriorly, in the middle of their length, a very prominent flat 

 protuberance. The manchbularies show a slight swelling in front, 

 corresponding with an accumulation of the villiform teeth. 



The dentition is formed by %'illiform bands only, without any 

 canines or granular prominences. The bands on the jaws reach to 

 the posterior extremity of the bones ; but, whilst those of the inter- 

 maxillaries are nearly equally broad in their whole length, those of 

 the mandibularies are broadest in front and tapering behind. The 

 vomerine teeth are arranged in two narrow and short bands, meetin'g 

 at a right angle ; the palatine teeth form a narrow band, extending 

 far on the pterygoid bone. The te*- th of the pharj^ngobranchials form 

 two broad patches on each side, with several smaller ones besides. 



The infraorbital arch is rather narrow and nearly equally broad, 

 the prseorbital widening anteriorly ; its ossification is complete ; but 

 there may be seen trai-es of a very narrow channel, covered on the 

 outside with streaks of a thin meinbrane, — a structure much more 

 developed in other genera of this family and in many other fishes. 

 The lower edge of the arch is serrated. The prseorbital is strongly 

 armed with eight or nine spinous teeth, directed backwards, the 

 anterior jnid posterior of which are very strong. TTie turbinal bone 

 o^'orreachcs the intermaxillary, with a prominent and bifurcate spine. 

 The posterior part of th^ hinder opening of the nostril has two very 

 small spines, reaching into the cavity ; they may be easily lost by 

 a less careful preparation of the skull. The inner parts of the 

 orbital cavity arc formed as in J/, ruhrum. 



