tfEOCOMlAN ROCKS OF COMEN, NEAR TRIESTE. 



55 



the distal end to 3 millims., which about corresponds to the proximal 

 width of the tibia. The tarsal bones (fig. 2, ts) are not well preserved, 

 but appear to consist of one large bone below the tibia, which is appa- 

 rently polygonal, and two smaller bones placed below the fibula ; but 

 there has probably been at least a third bone, which was distal in 

 position and is not preserved. The metatarsus (fig. 2, mi) is not very 

 distinct ; and it is difficult to say whether the metatarsal bones were 

 entirely distinct from each other. The specimen would appear to 

 indicate that there were at least three metatarsals. The bone 

 below the large tarsal element is short and broad, reminding one in its 

 proportions of that of a Plesiosaur. It articulates by a large proximal 

 facet with the large tarsal bone, and by a small facet at the proximal 

 end with the distal tarsal element adjacent to it. Its width at the 

 proximal end is over 2 millims. ; and it appears to be about 4 millims. 

 long. The metatarsals on the outer side are not preserved. There are 

 five digits (fig. 2, i-v) formed of slender bones with a median groove 

 on the dorsal surface of the first row. There are two bones in the first 

 digit, which is short and terminates in a pointed bone, the distal end of 

 which is a little curved and apparently carried a claw. There are 

 three bones in the second digit, which is about twice the length ; 

 but the fracture in the slab passes through the middle of the ter- 

 minal small phalange. In the third digit there majr have been four 

 phalanges ; but the fracture passes through the third, which is so 

 large that it is not likely to have carried a claw. There appear to 

 have been four phalanges in the fourth digit ; and in the fifth the 

 number cannot be satisfactorily determined ; but there do not appear 

 to have been more than three. The three inner digits have the 

 proximal surfaces of the proximal row of bones in the same line ; 

 but the two outer digits look as though placed a little higher up, 

 which is in accord with the ordinary Lizard plan. The total length 

 of the longest digit as preserved is about 9 millims. ; and the total 

 length from the proximal end of the tibia is a little over 21 millims. 

 It will thus be seen that the tarsus and digits differ considerably 

 from those indicated by the animal described as Hydrosaurus lesi- 

 nensis. 



It is of course with this type that the present specimen must be 

 chiefly compared ; and the form and proportion of the dorsal ver- 

 tebrae, the mode of articulation of the ribs, and the characters of the 

 caudal vertebrae, especially in the neural spine and transverse pro- 

 cess, indicate a distinct type. The pelvis is also distinct, while the 

 proportions of the segments of the limb differ in as remarkable a 

 way, and necessitated/placing this fossil in a distinct genus. Though, 

 from the imperfect preservation of the specimen, its more important 

 characters remain unknown, it may be conveniently distinguished 

 as Adriosaurus Suessii. Its affinities need the assistance of more 

 perfect remains for their elaboration. 



I am indebted to Prof. Suess for the opportunity of making this 



ecord, and adding another species to the Secondary representatives 



f the lizard group. 



