1916. |] S. Kempe: Notes on Crustacea Decapoda. 375 
tocaris; the latter term should therefore lapse., Aegeon orientalis 
agrees with Parapontocaris in the complete absence of the hepatic 
groove and in the arrangement of the carinae on the first and second 
abdominal somites and resembles typical Aegeon in the very broad 
antennal scale and in the possession of strong median spines on the 
abdominal sterna. Aegeon habererit and Jacazei are closely allied 
forms; in most respects they agree closely with typical species of 
the genus, but they resemble Parapontocarts in the sculpture of the 
first two abdominal somites and in the elongate form of the anten- 
nal scale. 
In all six species of Aegeon are known from Indian waters; 
they may be distinguished by the following key :-— 
I. Second lateral carina of carapace interrupted anteri- 
orly by a well defined hepatic groove; lateral parts of 
1st and 2nd abdominal somites irregularly lobed, with- 
out sharp longitudinal keels continuous with those on 
carapace. 
A. Median carina of carapace with 4 teeth ; two or 
three tubercles, forming an oblique transverse 
row, between median and rst lateral carinae ... cataphractus 
(Olivi). 
B. Median carina of carapace with 8 or 9 teeth or 
serrations; surface between carinae of cara- 
pace smooth, without tubercles. 
1. Marginal carina of carapace smooth ; 
two lobules separated by a vertical fur- 
row on either side of median carina of 
2nd abdominal somite Es ... pennata, Bate. 
2. Marginal carina of carapace serrulate ; 
a sinuous longitudinal ridge, entire and 
not divided bya furrow, on either side 
of median carina of 2nd abdominal 
somite ah AoE ... pvopensalata, 
Bate. 
II. Second lateral carina of carapace not interrupted, hep- 
atic groove absent ; lateral parts of ist and 2nd ab- 
dominal somites with sharp longitudinal keels conti- 
nuous with those on carapace. 
A. ist and 2nd lateral carinae of carapace with 
7 teeth, marginal with 7 to 9; antennal scale 
as broad as long BG se ... ovrtentalts, 
Fenderson 
B. ist lateral carina of catapace with 4 teeth, 2nd 
lateral with 3 to 6, marginal with 2 or 2e 
antennal scale much longer than broad. 
1. 2nd lateral carina of carapace with 5 or 6 
teeth, marginal with 3; median carina 
of 2nd abdominal tergum bispinous ... andamanense 
(Wood- Mason). 
2nd lateral carina of carapace with 3 
teeth, marginal with 2; median carina 
of 2nd abdominal tergum unispinous ... bengalense 
( Wood- Mason). 
No 
Aegeon cataphractus (Olivi). 
1900. Aegeon cataphractus, Stebbing, Marine Invest. S. Africa, I, p. 50 
(whi syn.). 
1905. Azegeon cataphractus, Pearson, Ceylon Pearl Oyster Fish., Macrura, 
eo) 
p- 59. 
