DR. RICHARDSON'S DESCRIPTION OF AUSTRALIAN FISH. 107 



being in fact almost identical with that exhibited by Maina vomerina. There is a groove 

 on the back formed by two scaly fillets for the reception of the dorsal fin as in Gerres ; 

 the fin itself is very deeply notched between its spinous and articulated portions ; the 

 preoperculum is minutely and obscurely crenated or quite entire, the operculum ter- 

 minates by a slightly concave line, without projecting points, and the suboperculum 

 passes beyond it in a narrow flexible tip, which forms the extremity of the gill-cover. 

 The suborbitar is quite entire ; the head is scaly on its upper surface as far forward as 

 the nostrils, but on its sides the scales are distributed as in the other Mecnoidea. The 

 ventrals are still farther back than in Ceesio. The creca are few, as in the Sparoidem 

 in general. None of these characters are foreign to the Manoideee as a group, yet they 

 do not exist so combined in any established genus, and Latris hecateia exhibits in 

 addition some particulars of structure not to be found in any described msenoid fish : — 

 viz. scales having even edges without teeth or cilia, and in fact perfectly cycloid ; no 

 elongated scales at the ventrals ; and simple lower pectoral rays projecting slightly 

 beyond the membrane. The simplicity of the pectoral rays is considered by Mr. Gray 

 to be of sufficient importance to constitute the basis of a family group, and Baron Cuvier 

 never ranks it lower than as a generic mark. It occurs most frequently, and in the 

 greatest variety of form, in the cottoid family, is common among the Gohioidea, and 

 characterizes several percoid and scisenoid genera ; but until the discovery of Nemadac- 

 tylus and Latris, it was not known to exist in any group connected with the Sparoidea, 

 Mainoidete, or Scomberoidea. It appears to be a peculiarity of structure not uncommon 

 among the fish of Van Diemen's Land. 



A small aberrant percoid group, the Theraponini, comprising the genera Nandus, 

 Therapon, Datnia, Pelates, and Helotes, approaches the Manoidea in several cha- 

 racters. Tlius in Nandus the percoid characteristic of armed gill-covers is reduced 

 to the mere vestige of a point on the operculum, and in Pelates to two points so feeble 

 as to be scarcely perceptible, while the preoperculum is not more serrated than in the 

 msenoid Gerres. None of the group have more than six branchiostegous rays, and Pe- 

 lates quinquelineatus has only six pyloric caeca, these appendages being altogether want- 

 ing in Nandus as in the Labri, while the air-bladder is simple and the jaws protractile 

 as in the MainoideiE. The rest of the members of the group have the air-bladder divided 

 in the middle by a contraction like the Cyprinoidecs, Characini, and Myripristes ; but in 

 the MaenoidecB this viscus has a simple body, though in many instances it gives out 

 posteriorly two horn-like processes. The scales of the Theraponini are ciliated as in the 

 McenoidecE ; but none of them have the long scales at the base of the ventrals, which 

 occur in all the ManoidetB except Latris. In both groups the prevailing distribution of 

 the darker colours is in longitudinal stripes, which is the case also with Latris hecateia, 

 and both its generic and specific names were in fact suggested by the resemblance 

 which it has in this particular as well as in others to the Theraponini and Meenee ; 

 AoTjoie, serva vel ancilla, being nearly similar in signification to Therapon, Helotes, and 

 Dules ; and as the Mediterranean fish which was termed Mao-ie by the ancients (whence 



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