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



Suspensorium directed obliquely backwards ; 

 vent equidistant from gill-openings and 

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



B. Frontals anlcylosed 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 weU 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- 



tebrfe without transverse processes 11. Muranesocidce. 



Maxillaries ai'ticulating with ethmoid near end 

 of snout ; caudal vertebrae with transverse 

 processes 12. Conyridcp. 



b. 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. Echelidce. 



No caudal tin ; ribs feeble 14. Opldchthyidce. 



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, Dysommidts, 



Gill-openings confluent ; palato-pterygoid very 



slender, almost vestigial 17. Synaphohranchidcs. 



Family 1. UrenchelidaB. 



Cretaceous eels with the caudal fin f lee from the dorsal and 

 anal. Several specie.? of Urenchelijs have been described by 

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

 Anguillavus hathshehce, 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 fins; these are small, 8-rayed, abdominal in position. 



I here designate this species as the type of the genus 

 AnguillavuSj for, in my opinion, Anguillavus quadriphinis 

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

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

 the body as far back as the pelvic fins is preserved, there is 

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

 in AnginllavHs and UrencheJys ; on the other hand, there are 

 traces of lateral rows of bony plates, unknown in these 

 genera. 



Dr. Hay's description of maxillae "parallel with the 

 premaxillw," and of supramaxillse, palatines, entopterygoids, 



