162 



SCIENCE. 



[Vol. II., No. 27. 



"O.C fO, 



Fig. 2. — Dorsal, ventral, lateral, and posterior views of the 

 skull of Muraenopsis tridactylus (life-size), respectively rep- 

 resented in A, B, C, and D, wbere like lettering has the same 

 indication in each view. Pma:, premaxillary ; Fo, vomer; ma:, 

 maxillary ; s. e, splen-ethmoid ; pa. «, parasphenoid ; pt, ptery- 

 goid; $9, squamosal; ca, columella auris; e.o, exoccipital; 

 o. c, occipital cordyle ; pn, foramen for exit of pneuraogastric 

 and glosso-pharyngeal nerves ; erm, external nasal aperture ; 

 JTo, nasal; F^ frontal; p, parietal; on^ foramen for the pas- 

 sage of of the orblto-nasal nerve, the first division of the fifth 

 pair, to the rhinal cavity ; os, orbito-sphenoidal region ; pr. o, 

 pro-otic; d, dental element of mandible; an, angulae; fm, 

 toramen magnum ; pi, roof of the mouth. 



sections had been made? And four hours and 

 a half after, when all the organs had been re- 

 moved, and inroads made upon the trunk, this 

 creature would still writhe vigorously by simply 

 pinching his tail, or close his jaws like a vice 

 in a way that would put the hardiest of eels to 

 shame, and crush anj' claim the latter might 

 have in standing at the head of the list of those 

 animals most tenacious of life. AVe find the 

 cranium of Muraenopsis ver3' thoroughly ossi- 

 fied, and manj- of the sutures observable only 

 after close inspection. The teeth ai-e of the 

 pleurodont type, and may he seen in all stages 

 of development in the deep grooves that exist 

 in the mandible, the maxilla, the premaxilla 

 (which usuall^^ supports twelve), and the entire 

 inner margins of the descending plates of the 

 vomers, which meet each other anteriorly (fig. 

 2, A). A long, slender, spheu-ethmoid is in- 

 serted between these last bones, quite distinctly 

 seen on the inferior aspect. 



The premaxilla throws backward a nasal 

 process that overlaps the frontals abo\e, and 

 passes between the nasals. These latter seg- 

 ments are very much honeycombed and grooved, 

 — a characteristic which is adopted by the an- 

 terior extremities of the frontals and the upper 

 parts of the maxilla on either side. The co- 

 ronal suture is seen beyond, a demi-lozenge 

 shaped and elevated plate, developed b^' the 

 united frontals, directed backward (fig. 2, B). 

 Each outer margin of the parietal region 

 is raised into a curling crest, as if pushed 

 up bj^ the unusually large squamosals, which 

 lend to the lateral aspect of the skull of this 

 creature such a massive appearance. As in 

 other Urodela, a large columella auris is seen 

 on either side, external to the extensive pro- 

 cesses that project backward, to bear the 

 occipital condyles (fig. 2, D). A pro-otic is 

 well developed ; but it is difficult to determine 

 in the adult cranium whether a separate epi- 

 otic and opisthotic exist or not, though I am 

 strongly inclined to think they do not. The 

 pterygoids are completely ossified, and quite 

 extensive, horizontall}'- flattened, and curved 

 plates of bone, their anterior extremities being 

 prolonged with a fibrous tissue to form the floors 

 of the orbits. The lower maxilla is veiy deep 

 and solid ; and, although the meeting of the 

 dentar}- elements anteriorlj^ is quite extensive, 

 the symph3-sis is not firm. Nearl3- the entire 

 basicranial region is occupied bj- the wide- 

 spreading and anterioi-ly produced parasphe- 

 noid (fig. 2, A) , which, with its serrated margin, 

 articulates with the parallel vomerine plates 

 bej'ond . 



We have presented us for examination in 



