FISH FAUNA. 73 



PLECTOGNATHI. 

 MONACANTHIDiE.* 



BALISTES, Artedi. 

 Balistes, sp. 

 The upper jaw of a species of this genus was picked up on the beach by 

 Mr. Saunders. 



MONACANTHUS, Cuvier. 



MONACAKTHTJS HOWENSIS, sp. nOV. 

 U. 35. A. 31. P. 14.— 15. C. 12. 



The distance between the tip of the snout and the upper angle of the gill- 

 opening is three and two-fifths in the total length ; the body is compressed 

 and elevated, its height at the origin of the dorsal fin being two and one-fifth 

 in the same. The eye is of moderate size, placed far back on the head, and 

 not much below the frontal edge ; its diameter is one-fourth of the length of 

 the snout, two-thirds of the interorbital space, and four-sevenths of the 

 branchial slit, the upper angle of which lies slightly behind its posterior 

 margin, while the lower is opposite to the middle of the base of the pectoral 

 fin. The upper profile of the snout is slightly concave, while that of the 

 back is sinuous, and rises gently to the origin of" the rayed fin. Fins. — The 

 dorsal spine is strong, with an almost imperceptible convexity in front ; it is 

 inclined slightly backwards, and is situated above the middle of the orbit, 

 its height being fonr-fifths of the length of the snout ; it is armed with four 

 rows of short stout conical teeth, which are bent downwards, and the anterior 

 pair of which are much closer together than the posterior, and reach to the 

 extreme tip of the spine, which the latter do not ; the anterior and lateral edges 

 of the spine between the rows are covered with irregularly-set small rugo- 

 sities, especially on the basal portion. The origin of the soft dorsal is one- 

 ninth nearer to the end of the caudal fin than to the tip of the snout, while the 

 intradorsal space is but a fraction less than the length of the snout ; both the 

 dorsal and anal fins are moderately high, with a convex outer margin, 

 and the latter commences beneath the ninth dorsal ray ; the ventral 

 spine is of moderate size and immovable, and is furnished with 

 a lateral row of short conical teeth, the lower surface being also 

 covered with granular projections ; its tip is just half-way between the 

 tip of the snout and the end of the tail ; the pectoral fins are short, 

 slightly convex posteriorly, and rather less than the length of the snout ; the 

 caudal fin is rounded, its middle ray being one-sixth of the total length. 

 Scales. — The body is covered with small, spinate, transversely oblong scales, 

 and is without cutaneous appendages ; there are two pairs of short, upright, 

 conical spines on each side of the pedicle, the upper pair about equally 

 distant from the lower as they are from the dorsal profile. Colors. — Appear 

 to have been olive-brown with numerous round white spots on the sides of 

 the head and body ; the dorsal, anal, and pectoral fins are pale yellow, the 

 caudal dark brown. 



Mr. Etheridge's party obtained a single specimen, taken by hook in about 

 ten fathoms water between the main island and the Admiralty Islets, and 

 measuring rather less than eight inches. Register number, I. 1,566. 



OSTRACION", Artedi. 



OSTRACIOX CONCATENATUS, Bl. 



Is washed ashore commonly after heavy storms. 



OsTRACIOIi FORNASIXI, BiailC. 



Does not seem to be so common as the preceding species, nor to grow to 

 an equal size, but is obtained only by the same means. 



* See note on p. 55. 



