380 Mr. C. T. Regan on the OsleoJogy and 



Suspensorium directed obliquely backwards ; 

 vent equidistant from gill-openings and 

 end of short tail ; vertebrae about 80 ... . 10. Cyemidce. 



B. Frontals ankylosed to form a single bone ; pharyngeals oblong or 

 ovate, covered with small teeth ; pharyngeal openings of 

 branchial clefts wide. 



1. Jaws strong; suspensorium vertical or directed obliquely 



forwards ; palato-pterygoid well developed as an elongate 

 lamina. 

 a. Nostrils superior or lateral ; neural spines long and slender, 

 Maxillaries articulating with ethmoid at some 

 distance from end of snout ; caudal ver- 



tebra3 without transverse processes 11. Murcenesocidce. 



Maxillaries articulating with ethmoid near end 

 of snout ; caudal vertebrfB with transverse 

 processes 12. Congridcp. 



h. Nostrils labial ; neural spines vestigial ; maxillaries articu- 

 lating with ethmoid near end of snout ; caudal vertebrae 

 with transverse processes. 



Caudal fin present ; ribs strong 13. Echelida. 



No caudal fin; ribs feeble 14. Ophichthyidte. 



2. Jaws slender ; suspensorium directed obliquely backwards. 

 Gill-openings well separated; vent remote from 



head '. '15. Ilyophidce. 



Gill-openings well separated ; vent not far be- 

 hind them ; no palato-pterygoid 16. Dyso^nmidte, 



Gill-openings confluent ; palato-pterygoid very 



slender, almost vestigial 17. Synaphobranchidce. 



Family 1. Urenchelidae. 



Cretaceous eels with the caudal fin free from the dorsal and 

 anal. Several specie.s of Urenchel-jS have been described by 

 Smith Woodward (Cat. Foss, Fish. iv. p. 337, 1901). 

 Anguillavus baihshebce, Hay (Bull. Amer. Mus. xix. 1903, 

 p. 439, pi. xxxvii. fig. 1), from the Upper Cretaceous of 

 Mount Lebanon, is of great interest as an undoubted eel with 

 pelvic tins; these are small, 8-rayed, abdominal in position. 



I here designate this species as the type of tiie genus 

 Anguillacus, for, in my opinion, Anguillavus quadripinnis 

 (Hay, t. c. p. 437, pi. xxxvi. figs. 2 & 3) is the lepresentative 

 of another genus, and probably not an eel at all. Although 

 the body as far back as tiie pelvic fins is preserved, tiiere is 

 no trace of the dorsal fin, which begins just behind the head 

 in Anguillavus and Urenckelys ; on the other hand, there are 

 traces of lateral rows of bony jjlates, unknown in these 

 genera. 



Dr. Hay's descrijition of maxillse "parallel witii the 

 premaxillffi," and of supramaxillse, palatines, entoptery golds, 



