196 R. Bullen Newton—On Steneosaurus Baroni. 
which probably marks the passage of the pneumo-gastric nerve. 
The extremities of the lower occipital through injury are difficult 
to define. The anterior view of this part of the cranium shows a 
strong parietal ridge, extending about 10 cent. and separating the 
large temporal foss, the front portions of which are absent; width 
of the right fossa is 7 cent.; height from the top of the parietal 
ridge to the pterygoidal vacuity is 9-5 cent. ; this vacuity is strongly 
arched and measures at its greatest diameter 5-6 cent. 
All other parts of the cranium, such as the orbits, frontals, nasals,. 
palatines, etc., are unfortunately missing. 
Specirico AFFINITIES. 
Comparing this specimen with some of the described species of 
Steneosaurus, we may observe that S. Larteti though of somewhat 
similar dimensions has a larger number of teeth, a straight cranial 
rostrum, and a rather more depressed head. 
S. Stephani possesses more extensive temporal fossee and larger 
alveoli. 
S. megistorhynchus exhibits a much more extended and depressed 
cranium as well as more numerous teeth. 
S. megarhinus differs in having five alveoli to each preemaxilla. 
Not finding its exact representative among these various species, 
I propose to regard it as a new form, and this chiefly on account 
of its very narrow and cylindrical rostrum together with its marked 
undulation. The name proposed for the specimen is Steneosaurus. 
Baroni, out of compliment to its discoverer. 
The genus Steneosaurus has hitherto been restricted to British and 
European areas, so that the discovery of this reptile so far south 
as the Island of Madagascar is a matter of the highest interest when 
considering its geographical distribution. Sooner or later we shall 
hope to hear of its occurrence in the Jurassic rocks of the African 
continent, either in the neighbourhood of Mombasa or further north- 
wards among the Antalo Limestones of Abyssinia. 
Horizon.—As far as can be ascertained this genus has never been 
found out of Jurassic deposits. The few Molluscan shells associated 
with this new specimen tend to prove it of Lower Oolite age. These 
will be described elsewhere; in the meantime they may be referred 
to as (1) Mytilus, resembling M. Tigrensis, W. I. Blanford, from 
Abyssinia; (2) Modiola, similar in some characters to M. imbricata, 
Sowerby ; (3) Perna, related to P. quadrata, Phillips; and (4) a 
new species of Trochactgonina. 
EXPLANATION OF PLATE IX. 
1. Steneosaurus Baroni, sp. nov. Palatal view of the cranial rostrum. 
2. Left lateral aspect of the cranial rostrum showing its undulating character. 
», 8. Upper view of mandible, showing symphysis, splenials, etc. 
4. Basal view of mandible. 
5. Fragment of a dermal scute belonging to the ventral armour. 
Figs. 1-4 are 4 nat. size. Fig. 5 is $ nat. size. 
