320 Mr. C. T. Regan on the OstooJo(j>j and 



XXXV. — The Osteology and Classification of the Teh'oslean 

 Fishes of the Order Microcyprini. ^y C. Tate Regax, 

 M.A. 



(Publi.'^hed by perniissiou of the Trustees of the British Museum.) 



[Plate VIII.] 



As defined and limited in the ' ( Cambridge Natural History ' 

 the group Haplorai includes a numbn- of families of soft- 

 rayed fishes with abdominal pelvic fins, which are thrown 

 together because they lack the mesocoracoid bone, the presence 

 of which characterizes the order Isospondyli or Malaco- 

 pterygii. It was only to be expected that further study of 

 puch a large and heterogeneous group, defined by a single 

 negative ciiaracter, would prove it to be unnatural. 



I have already called attention to the fact that Retropinna, 

 Microstoma, and Safanx have no mesocoracoid *, altliough 

 they are closely related to the Argentinidse, in which that 

 bone is well developed. Moreovei-, Retropinna, which repre- 

 sents Osmerus in Australia and New Zealand, is a connecting- 

 link between the northern family Argentinidge and the 

 southern Haplochitonidae and Galaxiidae. All these fishes 

 are extremely similar in osteology, dentition, and other 

 characters, and are very closely related. The Haplochitonidae 

 and Galaxiid^, then, are not Haplomi, although they have 

 lost the mesocoracoid ; they are Salmouoids. 



The third faniily of the Haplomi in the ' Cambridge 

 Natural History' is the Enchodontidse, Cretaceous fishes 

 which seem to me to be related to the Stomiatidae, which 

 they resemble in mouth-structure and in cranial osteology. 



I have already dealt with the osteologj' and classification 

 of many of the other groups included in the Haplomi by 

 Boulenger, viz. the Percopsidse (which I have united with 

 the Aphredoderidas to form the isolated order Salmopercae), 

 the Stephanoberycida (provisionally placed with the Melam- 

 phaidse in an order Xenoberyces, apparently related to the 

 Berycomorphi), the Scopelidte, Alepidosauridse, Cetomiraidee, 

 and Chirothiicidie, which with the Ateleopidro form the order 

 Iniomi, an offshoot from very primitive isospondylous fishes. 



The Kneriidaj have already been removed to the Isospondyli 

 by Boulenger (Cat. African Freshwater Fish.) ; this family 

 is not very remote from the Chanidse. 



* Ann. .t Mag. Nat. Hist. (><) iii. lOOP, p. 82. 



