496 Dr. F. Haas on new 



from the sandy shores of tropical and temperate seas ; many- 

 species enter rivers and some are permanently fluviatile. 



I have examined skeletons of Solea (vertebras 9-10 + 31-41), 

 Synaptura (9 + 41-48), Achirus (9 -f 20), Pardachirus 

 (10 + 27), and Liachirus (10 + 23). Achirus is certainly 

 generically distinct from Solea, but there are no structural 

 characters which entitle it to rank as the type of a distinct 

 subfamily, as in Jordan and Evermann's classification. 



Family 2. Cyncglossidse. 



Sinistral. Vertical fins confluent ; no pectorals ; pelvic 

 fin of blind side present, 4-rayed, median in position, that of 

 eyed side displaced upwards and reduced, or entirely wanting ; 

 pelvic bone of the reduced or absent fin much smaller than 

 the other. Vertebras 47-65 (9-10 + 38-56) . 



Principal genera : — Symphurus, Paraplagusia, Cyno- 

 glossus, from tropical and temperate seas. 



I have examined skeletons of Symphurus (vertebras 9 + 40), 

 Paraplagusia (9 + 43) , and Cynoglossus (9 + 56) . The skele- 

 ton is strikingly similar to that of the Soleidge, and there can 

 be no doubt that the two families are closely related ; as in 

 Achirus and other Soleid genera without pectoral fins, the 

 coracoid bones are absent. 



LV. — New Unionidse from East Asia. By Dr. F. Haas, 

 Senckenberg Museum, Frankfurt-a.-M. 



In preparing a continuation of Krister's Monograph of Unto 

 in the'Martini-Chemnitzsches Conchy liencabinet' I examined 

 a large number of shells, which, for the greater part, belonged 

 to the Senckenberg Museum or were purchased from 

 Messrs. Sowerby and Fulton, Kew, and Mr. H. Rolle, Berlin. 

 The East-Asiatic Unionidas of the Zoological Museum of 

 Berlin were also at my disposal. Among all these shells 

 I found the following new species and subspecies, the types 

 of which, with the only exception of Nodularia undulata, 

 belonging to the Berlin Museum, are in the collection of the 

 Senckenberg Museum, and which I shall figure in my mono- 

 graph mentioned above. 



1. Nodularia denserugata, sp. n. 

 Shell elongate-elliptical, rather solid and inflated, rounded 



