1G8 



Mr. G. A. BouleDger on the Suborders and 



Anguillidce. 

 NemicWhrjidcs. 



skull, through reduction or loss of either the maxillary or the 

 pterygo-palatine arches. 

 Five families : — 



Maxillaries present, separated on the median line 



by the ethmo-vomer ; palato- pterygoid 



present, connected with the hyomandibular 



and quadrate ; gill-clefts separate, opening 



into the pharynx by wide slits ; tong-ue 



present ; vent i'ar removed from the head. . 1. 

 Distinguished from the preceding by the position 



of the Tent, whiih is close to, or at no great 



distance from, the gill-openings 2. 



Maxillaries narrowly separated on the median 



line, their extremity strongly attached by 



ligament to the mandible ; pterygo-palatine 



arch absent; gill-openings externally con- 

 fluent into a single ventral slit 3. SynaphobranchicUe. 



Maxillaries narrowly separated on the median 



Jiue, extremely elongate ; mouth enormous ; 



pterygo-palatine arch absent ; hyomandi- 

 bular arcli slender and movablj' articulated 



to the cranium ; branchial arches far behind 



the sliull 4. Saocopharyvyida;. 



Maxillaries absent, replaced by the palato- 



pterygoid, the moutli bordered by the latter 



and the ethrao-vomer ; palato-pterygoid 



bone separated from hyomaudibular arch; 



branchial openings into the phar3-irx narrow 



slits ; no tongue 5. Murceiiida;. ' 



Suborder V. 11 A P L M i. 



Air-bladder, if present, communicating with the digestive 

 tract by a duct. Opercle well developed. Pectoral arch 

 suspended from the skull ; no mesocoracoid arch. Fins 

 usually without, rarely with a few spines ; ventrals abdo- 

 minal, if present. Anterior vcrtebra3 distinct, without 

 Weljerian ossicles. 



The absence of the mesocoracoid arch distinguishes the 

 Haplomi from the Malacopterygii, with which they are 

 iniited by various authors. Tiiey lead to the Percesoces 

 through the Cyprinodontids, and to the Lower Acaiitho- 

 pterygians, such as the Berycids, through the Scopelids, 

 ^tephanoberycids, and Percopsids, as is evidenced by the 

 structure of the mouth and the forward position in some of 

 the genera of the ventral fins, which, however, are never 

 attached to the pectoral girdle. Most of the forms which 

 are here included inhabit either fresh waters or tlie deep sea. 



