systematic Position o/Luvariis imperlalls. 279 



and although Gill has separated it from them as the type of 

 a distinct family, he has still retained the Luvaridse among 

 the Scombroid fishes, near the Corypha3nid;e. 



I have arrived at the conclusion tliat the Luvaridae are 

 closely allied to the Acanthuridrci. A comparison shows that 

 in both families tiie body is oblong and compressed, the 

 dorsal and anal fins long, the caudal peduncle slender, the 

 caudal fin deep, the scales small, rounded, and usually rough, 

 covering- the head and body, and the lateral line concurrent 

 with the dorsal profile. In both also the gill-membranes are 

 broadly united to the isthmus, there are four gills, with a 

 slit behind the fourth, five branchiostegals, well-developed 

 pseudobranchise, and short gill-rakers. 



In Luvarus, as in the Acanthurida3, the mouth is small, 

 the premaxillaries are not protractile, and the maxillaries are 

 attached to them and not independently movable. The tooth- 

 less palate, the palatine arch attached only to the pre-ethmoid, 

 the coalescent pelvic bones, the separate lower pharyngeals, 

 and the upper pharyngeals much compressed antero-posteriorly, 

 are further points of agreement between the two families. 



Luvarus, like the Acanthurid^e, is a vegetable feeder, and 

 exactly resembles them in its visceral anatomy *. The 

 stomach is large and thick-walled, the pyloric appendages 

 short, simple, and few in number, and the intestine very long 

 and much coiled ; the air-bladder is large. 



The skeleton! of Luvarus resembles that of the Acau- 

 thuridge in many features. The most striking correspondence 

 is seen in the vertebral column, the vertebrse numbering 

 twenty-two in both cases, the first being very short and more 



about the fourteenth, which is as Ling as the head in the young, shorter 

 in the adult, the last 10 rays branched, the anterior rays wider apart than 

 the rest. A. 17-18, similar to the dorsal. In large specimens, D. 12-14, 

 A. 13-15, the anterior rays having disappeared, their interneurals and 

 interhfemals forming bony ridges in the dorsal and ventral middle lines 

 respectively ; some specimens (? males) with the first ray of the reduced 

 fins more or less elongate. Pectorals elongate, nearly -j the length of 

 body. Ventrals I 4, slightly in front of the pectorals, the soft rays elon- 

 gate in the young and absent in the adult. Caudal peduncle slender, 

 keeled in the adult, caudal deeply lunate. Scales very small, rough, 

 shagreen-like. Bluish above, silvery below and on the sides. Fins red. 

 The young with 5 or 6 longitudinal series of round black spots on the 

 sides and dark dorsal and anal fins. 



* For the visceral anatomy see Cuv. & Val. ix. p, 358, and compare 

 with Acanthuridfe described in vol. x. Also Nardo, ' De Proctostego,' 

 1827, and Haller, i.Q Krukenberg, Vergl. Physiol. Stud. iv. 1881, p. h 



t Giiuther (Proc. Zool. Soc. 18G6, p. 336)"gives a short description of 

 the skeleton, with a plate (not well executed). 



