1900.] NEW GENUS OF FLAT-FISHES. 991 



of the abdominal cavity the oesophagus is continued without visible 

 division into the stomach, and this directly into the somewhat 

 narrower intestine. The first coil of the latter inclines towards 

 the blind side, where it lies along the first interhaemal spine within 

 the secondary abdominal cavity of the blind side. The intestine 

 then bends forward again into the main body-cavity, where it forms 

 a coil ventral to the stomach. It then passes backward into the 

 secondary cavity of the eyed side, where it forms a long coil with 

 many foldings. Its exact posterior limit was not dissected out, but 

 it seemed to occupy the whole of the secondary abdominal cavity. 

 The vent is situated immediately posterior to the sixth or last ray 

 of the ventral fin of the blind side. 



The abdominal cavity is comparatively large and is bounded 

 posteriorly by a strong first interhaemal spine. This is continued 

 forward on the ventral edge of the abdomen by cartilage and 

 ligament as in the Turbot group, so that the termination of the 

 spine, i. e. the so-called anal spine, does not appear externally. 

 The abdominal vertebra; are of the ordinary type found in the 

 Plaice and Turbot ; they do not have ha?m apophyses. Secondary 

 ribs are present on the second to the tenth vertebra. Parapophyses 

 and primary ribs are present on the third to the tenth. 



It is necessary, in conclusion, to point out the affinities of this 

 form. In a previous paper (181 h Annual Keport of the Fishery 

 Board for Scotland, part iii. p. 360) the flat-fishes of the Xew 

 Zealand fauna except Brachypleura were grouped together within 

 one subfamily, Solei-plenronecthur. The characters of this sub- 

 family are as follows : — 



(!) Preopercular margin distinct, not hidden by the skin and 

 scales of the head. 



(2) Olfactory laminfe arranged longitudinally without median 



rachis. 



(3) Ventral fins asymmetrical; two or one. 



(4) Xasal organ of blind side lies anterior to the anterior 

 extremity of the dorsal fin (?). 



(5) Mouth asymmetrical, dentition more developed on blind 



side ; gape small ; underjaw more prominent. 



(6) Eyes on right side. 



The form described here agrees with characters (1), (2), (3), and 

 (5). Further, although not given as one of the characters of the 

 subfamily, one of the ventral fins (that of the eyed side) is joined 

 to the anal fin in all these New Zealand forms. The American 

 form Oncopterus, which has been included provisionally within this 

 subfamily, differs from these in this respect. Character (4) — the 

 position of the nasal organ of the blind side — was unknown for 

 the Xew Zealand forms previously described, and it is possible 

 that these agree with the present form in having the nasal organs 

 one on each side of the dorsal fin. The present form differs from 

 the others, however, in that it has the eyes on the left side. A 

 further difference of importance lies in the formation of the 



