FLATFISHES. NORMAN. 261 



Six genera from Australia and New Zealand, and 

 one (Oncopterus) from Patagonia. Psammodiscus 

 (habitat unknown) also belongs to this subfamily. 



Synopsis of the Genera. 



I. Two pelvic fins. 



A. Right pelvic free from anal. 



1. Lateral line with a strong curve anteriorly; right pelvic 



with six rays. 



a. Lateral line with several transverse accessory 



branches; no anal spine 1. Oncopterus 



b. Lateral line with a single accessory branch; anal fin 



preceded by a spine 2. Psammodiscus 



2. Lateral line with a slight curve anteriorly; right pelvic 



with 10 or 11 rays 3. Azygopus 



B. Right pelvic joined to anal. 



1. Dorsal commencing above eyes; snout not produced 



4. Pelotretis 



2. Dorsal commencing in front of eyes; snout produced 



into a fleshy hook. 



a. Mouth visible on ocular side; none of the rays of right 



pectoral produced. 



* Olfactory laminae parallel, without rachis; dorsal 

 and anal rays scaly, without basal sheath 



5. Ammotretis 



** Olfactory laminae arranged in pinnate form, with 

 short rachis; dorsal and anal rays naked, a low 

 scaly sheath at base on ocular side . . 6. Colistium 



b. Mouth not visible on ocular side; upper ray of right 



pectoral filamentous 7. Peltorhamphus 



II. One pelvic fin 8. Rhombosolea 



3. AZYGOPUS, gen. nov. 



Eyes narrowly separated, the upper rather close to 

 the dorsal profile. No rostral hook. Nasal organ of 

 blind side nearer median line of head than that of ocular 

 side, and below origin of dorsal fin; olfactory laminae 

 arranged in pinnate form, with a fairly long median 

 rachis which is parallel to the main axis of the body. 

 Mouth rather small, subsymmetrical ; teeth small, 

 movable, pointed, in bands in the jaws; almost entirely 

 confined to blind side. Lower pharyngeals moderately 

 broad, curved, in contact anteriorly, each with three or 

 four irregular series of teeth. Upper angle of gill- 

 opening just above base of pectoral fin; gill-rakers in 

 moderate number, short. Dorsal fin commencing just in 

 front of eyes and above nasal organ of blind side; none 

 of the rays scaly ; a low scaly sheath covering basal parts 

 of fin on ocular side. Anal fin similar to dorsal; no 



