1892.] Electromotive Properties of the Skin of the Eel. 391 



only one (the lower) post-temporal fossa open on each side. The 

 maxilla is produced into a tooth-like prominence, which occupies a 

 similar position to the tusks of Gordonia ; but the bone is too thin to 

 have supported a tooth, and in all probability it was covered by a 

 horny beak. The lower jaw has a strong symphysis, a distinct lateral 

 vacuity, and the oral margin, at the front of each ramus, bears a 

 rugose prominence. 



Elginia mirabilis is the name proposed for the skull of a Reptile, 

 which, on account of the extreme development of horns and spines, 

 reminds one of the living Lizards Moloch and Phrynosoma. The ex- 

 terior of this skull is covered in by bony plates, the only apertures 

 being the pair of nostrils, the orbits, and the pineal fossa. The 

 surfaces of the bones are deeply pitted, as in Crocodiles and Laby- 

 rinthodonts. The horns and spines, which vary from J in. to nearly 

 3 in. in length, are found upon nearly every bone of the exterior. 

 The development of the epiotics and the arrangement of the external 

 bones resemble more the Labyrinthodont than the Reptilian type of 

 structure, while the palate, on the other hand, conforms more nearly 

 to the Lacertilian type, and, with the exception that the pterygoids are 

 united in front of the pterygoid vacuity, agrees with the palate of 

 Iguana and Sphenodon. There are four longitudinal ridges along the 

 palate, some of which seem to have carried teeth. The oral margin 

 was armed with a pleurodont dentition, there being on each side 

 about twelve teeth with spatulate crowns, laterally compressed and 

 serrated. With the exception of the smaller number of the teeth, we 

 have here, on a large scale, a repetition of the dentition of Iguana. 

 This peculiar skull seems to show affinities with both Labyrinthodonts 

 and Lacertilians, and is unlike any living or fossil form ; its nearest, 

 though distant, ally apparently being the Pareiasaurus from the Karoo 

 Beds of South Africa. 



III. " The Electromotive Properties of the Skin of the Common 

 Eel." By E. WAYMOUTH REID, Professor of Physiology in 

 University College, Dundee. Communicated by Professor 

 M. FOSTER, Sec.R.S. Received November 19, 1,892. 



(Abstract.) 



1. The assumption that the E.M.F. of the current of rest of the 

 skin of the Fish is entirely due to mucin-metamorphosis, and that it is 

 not possible to attribute it to the presence of glandular elements is 

 negatived, in the case of the Eel, by the absence of any such mucinons 

 change in the superficial epidermic cells and by the presence of abund- 

 ance of secretory cells throughout the structure. 



2 D 2 



