218 DR. MALCOLM SMITH ON 
shield formed by 16 or 17 transverse, and 4 or 6 longitudinal, series of 
bony scutes, which are joined to each other in a transverse series, as in 
CO. palustris, by suture. In the arrangement of the shields upon the 
under surface of the body these two species also resemble each other, 
but differ from C. porosus, in that, across the pectoral region, there is 
a single row of much enlarged scutes (PI. 6, fig. A.), the shields forming 
this series being from two to three times as large as those of the adjacent 
rows. In the diagnosis of juvenile specimens this character is very useful. 
The feet. A rudiment of a web between the inner four fingers. Web 
between the toes much shorter than in C. palustris or porosus. I have 
no examples of C. palustris suitable for examination, but Mr. Boulenger 
has kindly examined spirit specimens for me in the British Museum 
and writes that there is not much difference in palmation between it 
and porosus; in both the web between the 3rd and 4th toes reaches 
practically the extremity, but it is rather more deeply notched between 
the 2nd and 8rd toes in palustris. In siamensis the web between the 
3rd and 4th toes does not reach the extremity, while between the 2nd 
and 2rd toes it barely reaches the 2nd joint of the latter. 
This shortness in the web of the toes of C. siamensis, as compared 
with that of CO. porosus, is well known to the people of Siam, and is 
commonly used by them to differentiate between the two species, 
“takhé tin kai” the fowl-footed crocodile, being used for the former, 
and ‘‘takhé tin pet” the duck-footed crocodile, for the latter. Their 
application of this knowledge, however, is by no means certain, and 
when confronted with the creature, they are seldom in agreement as to 
which kind they are actually dealing with. 
Dimensions. The largest individual [ have actually measured 
was 3.50 metres in length, and [ have never seen any which appeared 
much bigger, although many that were quite as big. The skull of what 
seems to be an aged individual in my possession, is no longer than that 
of the above mentioned example, and 3.50 to 4 metres probably repre- 
sents the average maximum length of this species. The tail constitutes 
approximately one half of the total length. 
Distribution. Indo-China, Siam, ? the Malay Peninsula, Java. 
[In Central Siam, upon the Me Yome, Me Ping, and the Prasak 
rivers, it is still fairly common, although large numbers have been shot 
by Europeans of recent years. In Northern Siam it appears to be 
JOURN, NAT. HIST, SOC, SIAM, 
