Classification of Teleostean Fishes. 83 



orbitosphenoid are absent, the parasphenoid unites with the 

 spenotic (post-frontal) in front of the prootic, the post-tem- 

 poral is simple or ligamentous, the scapula is lamellar and 

 imperforate, the preecaudal vertebree have autogenous para- 

 pophyses, epineurals are present, &c. 



Haplomi. 



The Haplomi as now restricted comprise only the Umbridae, 



Esocidse, and Dalliidse, a very primitive group agreeing with 

 the Isospondyli in mouth-structure, but unique in the character 

 of the paired ethmoids. 



Apodes. 



I have defined the Apodes as lacking prsemaxillarie?, and 

 I am very sceptical as to their presence in Derichihjs. If we 

 neglect this character, Denchthys is very similar to the 

 Anguillidse, in many of which (e. g. Conger) there is what 

 may be a prgemaxillary dentition distinct from that of the 

 vomer, although there is no separate prajmaxillary bane. 

 Dr. Gill does not tell us that he dissected his specimen of Der- 

 ichthys serpentinus in order to ascertain tlie limits of the 

 prgemaxillaries, and it seems not improbable that he may have 

 inferred the presence of these bones as separate elements 

 from the presence of a well-defined praemaxillary dentition. 



The Cretaceous Anguillavidse and Urenchelidas have a 

 distinct caudal fin, and small abdominal pelvic fins are 

 present in the former. 



Lyomeei. 



The presence of parietals, the transverse processes anky- 

 losed with the centra, the restricted gill-openings, &c. indicate 

 the derivation of the Lyomeri from the Apodes and not from 

 the Stomiatoids. The Synaphobranchida3 approach them in 

 their rather broad skull, long slender maxillaries, backwardly 

 directed suspensorium, absence of pterygo-palatine arcade, &c. 



Iniomi. 



The order Iniomi includes the Aulopidee, Synodontidae, 

 Odontostomidge. Paralepidse, Alepidosauridse, and Mycto- 

 phidse ; probably also the E,ondeletiida3 and the extinct 

 Chirothriciclse and Dercetidse. The name Iniomi may be 

 retained for this group, although in Aulopus the forked post- 

 temporal is firmly attached to the epiotic above and the 

 opisthotic below ; tliis generalized type has two supra- 

 maxillaries and shows considerable resemblance in cranial 



