Classification of the Order Tniomi. 121 



Suborder 1. Myctophoidea. 



Caudal well-developed, free from the anal ; pectorals 

 Literal; pelvics 6-11 rayed, below or behind the pectorals. 

 Mouth terminal, not or but little protractile. Palatine nor- 

 mally developed, its anterior end attached to the vomer, with 

 a process directed upwards and outwards which overlaps the 

 proximal end of the maxillary and is supported by a lateral 

 projection of the mesethmoid ; interoperculum not reduced. 

 Cleithrum attached to supracleithrum at the lower end of 

 the latter ; postcleithrum, when present, laminar, attached 

 by its anterior edge to inner face of supracleitiirum or 

 cleithrum. 



Family 1. Aulopidae. 



The fishes of the genus Aulopus are in many ways the 

 most generalized members of the order; the form is moderately 

 elongate, little compressed ; the scales are of moderate size ; 

 the eyes are lateral and the slightly protractile terminal 

 mouth is rather wide, the maxillary extending back to below 

 the posterior pait of the eye or beyond ; the maxillary is 

 dilated posteriorly and bears two supramaxillaries ; the small 

 conical teeth form narrow bands in the jaws and on the 

 palate, the palato-pterygoid bands being connected in front 

 by that of the vomer. The branchiostegal rays are long, 

 curved and rather numerous (10 to 16), the dorsal fin com- 

 mences a short distance beiiind the head and is rather 

 elongate, and the Avidely separated 9-rayed pelvic fins are 

 inserted below or a little beliind the pectorals, wliich are 

 placed rather low down on the sides. There is no air- 

 bladder. 



The skeleton of Aulopus is well ossified ; the skull is 

 rather elongate, without crests on tlie flattish upper surface, 

 which is nearly at right angles to the posterior surface. The 

 parietals meet above the supraoccipital and with the pterotics 

 roof the posterior temporal tossa3 ; the cranium broadens out 

 behind the orbits and the sphenotic has a prominent process 

 directed outwards and downwards; the subtemporal fossa is 

 moderately deep; the orbitosphenoid is a vertical lamina 

 extending from the frontals to the parasphenoid and forming 

 a septum in the anterior half of the interorbital region ; 

 posteriorly it is separated from the alisphenoids by a pair of 

 inferior ridges of the frontals ; the parasphenoid widens out 

 anteriorly on each side into a broad lamina which unites with 

 the lower edge of the lateral ethmoid; the latter is well 

 ossified, but is separated fiom its fellow by a wide interspace ; 



