ON THE CLASSIFICATION OF THE LABYRINTHODONTS. 157 
wards) in front of the orbit; there is a maxillary groove, and upon the mandible a 
descending and a horizontal groove, as in Mastodonsaurus. Thoracic plates. A 
fragment of a lateral thoracic plate, which is probably referable to this genus and 
species, shows a radiate sculpture upon the external surface; the postero-external 
angle is reflected. 
Measurements (from Prof. Huxley’s Memoir). 
in. 
Donen th attoreypant Of Orbits ..{.pud ee. afumreaoalin). Vasile 6 »,9 bere ete 1:06 
Least distance between palatine foramina and choane .......... 5 
Greatest depth of mandible .............sceeeeeeeeeee (about) ‘5 
Length of postarticular process of mandible .............0eeeaee 7 
G. Lonerrostris, Huxley. 
Locality. Panchet Rocks (Triassic ?), Ranigunj, Bengal. 
References. Huxley, Paleontologia Indica: Part IV. On Vertebrate Fossils 
from the Panchet Rocks, p. 1, t. vi. figs. 1, 2, 3-8? [1865]. 
Metopias, Von Meyer. 
Skull (figure). Triangular, with obtuse snout and scmewhat convex sides; 
posterior border unknown. Orbits. Far forwards, oval, small, distant, converging 
in front. Eaternal nasal foramina. Large, oval, separated by about half the inter- 
orbital space, converging in front. Palatine foramina. Large, broadest in front and 
towards the middle, somewhat contracted behind, approximated. Choane. Directly 
in advance of palatine foramina, and distant about half an inch from them, oval, con- 
verging in front, more distant from each other than are the external nasal foramina, 
situate upwards of 13 in. further back. Teeth (disposition). Premaxillary and maxil- 
lary unknown ; palato-vomerine, large tusks in series, with very numerous small 
teeth, a transverse row of small vomerine teeth in advance of the choane ; mandibular 
imperfectly known, a few of rather large and uniform size have been found together 
in one example. Teeth (structure). Conical, dilated towards the tip, blunt, striate. 
Cranial sculpture. Strongly pitted, with radiating grooves towards the margins of 
the ossifications ; a deep oe conspicuous lyra, beginning in the interorbital space, 
rather behind the orbits, expanding into a nearly circular figure upon the face, and 
much contracted between the external nasal foramina. A sell -rilarlied malar 
groove™. 
Measurements. Fa 
RRP ee DRO R CMO MBE UN 20d scil -is) ssp apenas Sfustieyarausl\oaysy (about) 12 
Breadth at middle of orbits...............+-e00- (upwards of) 8 
Resa EAC MO ROGUE eectiseogsy cotter tek h ah iat o 5 ala shaai'n1acesa ie: oxniacnsi sis) esis ayeye laa) ous 16 
\WWICHIRT OOH OH. see Ge ROAR REED Gane OOr OPH. Oe acre 1:25 
Least width of interorbital space ..............ecceeeeeeeeees 31 
Distance between external nasal foramina............-.000ee005 16 
Bengt Or Palmira OTAMEN | oi 6... cis ojs.e cone e on wis a mpeleiejeis,aihie,« 65 
WV YGU OE RATAN ok a sei one leno eetnneedivee ae 2:25 
Least distance between palatine foramina.................00005 1 
Average length of mandibular teeth .................... (about) ‘5 
Diameter of largest palato-vomerine tusk ,...............000005 “4 
M. praenosticus, Von Meyer. 
Locality. cE: Keuper Sandstone of Stuttgart; Rhetic of Aust Cliff, near 
Bristol. 
References. Von Meyer & Plieninger, Paliontologie Wiirttembergs, pp. 18, 75, &c. 
t. x. fig. 1, t. xi. fig. 11— Von Meyer, Saurier des Muschelkalkes, p. 146,'t. lx., 
_ t. Ixi. fig. 3, t. Ixiv. fig. 10. 
There is a skull in the British Museum, from which part of the above descrip- 
tion has been taken. The Rhxtic example quoted is in the Bristol Museum. 
* Only the internal half of this is shown in Von Meyer's figure (‘ Saurier des Muschel- 
kalkes,’ pl. 1x.), ‘ 
