an Amphibian from South Africa. 



341 



(cf. Ricnodon), (B.M.KH. R. 2818) from the Permian Gas Coal of 

 Nyran, Bohemia, there is a small median element in the roof of 

 the skull between the nasals and frontals. I propose to call the 

 anterior of these bones, that which occurs in MicropJiolis, the 

 internasal and the other the interfrontal. Their occurrence is 

 interesting in connection with the median bones so commonly found 

 in the skulls of Dipnoans, which are remotely allied to the Tetrapods. 



2. There is a distinct septomaxillare shown on each side in two 

 specimens. It is a little curved plate of bone lying inside the 

 nostril and articulating by its outer edge with the lachrymal. This 

 bone has only once been recorded before in a Stegocephalian, in 

 Eryops by Case ; it also occurs in ' Bothriceps ' Huxleyi. 



3. The arrangement of the bones round the orbit is extremely 

 unusual. The lachrymal is a large bone entering into the borders of 

 the orbit and nostril ; this condition, which obtains in many primitive 

 reptiles, is very rare in Stegocephalia. Tour of the skulls show very 



Fig. 1. MicropJiolis Stowi, Hux. Dorsal surface of anterior part of skeleton. 

 X 1. Skull with all sutures on upper surface from E. 510. VertebrsB, ribs, 

 shoulder-girdle, humeri from E. 510a. Forearm and hand and quadrate 

 from specimens in the Geological Society's Collection. Fr. frontal ; I.Teni. 

 intertemporal ; Ju. jugal ; Lac. lachrymal ; Mx. maxilla ; Na. nasal ; 

 P-Ma;. premaxilla; P.O. post-orbital; P. Par. post-parietal; Par. parietal; 

 Po.Fr. post-frontal ; Qm. quadrate ; Qu.J. quadrate- jugal ; S.Mx. septo- 

 maxilla ; Sq. squamosal ; Tab. tabular. 



clearly the course of the ductus naso-lachrymalis (Text-fig. 2), which 

 is a nari'ow canal running in the substance of the lachrymal bone 

 from the orbit, which it leaves by two openings, to the nostril, where 

 it opens below and behind the septomaxilla. This is, I believe, the 

 first recognition of a ductus naso-lachrymalis in the Stegocephalia,- 

 and the occurrence is very interesting from several points of view — 



{a) The very superficial position of the duct. In development in 

 recent types this begins merely as an epidermal thickening which 

 grows down into the head and subsequently acquires a lumen ; in 



