Classification of the Thalassinidea. 545 
C. secura, C. amboinensis, and C. cacigena. From these 
there stand off, on the one hand, the little group of C. ligni- 
cola and C. rotundicaudata, with shorter telson and a broader 
third pair of maxillipeds, and, on the other hand, the species, 
such as (’. subterranea, which have narrow third maxillipeds 
and a long telson, but also a lobe on the hinder edge of the 
propodite in the third pair of legs, whereby this lhmb takes 
on the shape which is typical of the genus. Hence, again, 
two lines branch out: one leads to such forms as C. gigas, 
which have still long telsons, but very broad third maxilli- 
peds; the other, containing such forms as C. brevicaudata, 
has a short telson, but often keeps the third maxillipeds fairly 
narrow. Between the two groups of which these species are 
typical there is, however, an almost complete series, and 
they cannot be sharply separated. 
Subgenera: Calliactites, Cheramus, Trypea, Callichirus, 
Scallasis. 
Subgenus CALLIACTITES, n. 
Definition: “Species of Callianassa with the maxillipeds 
of the third pair narrow or more or less broadened, no lobe 
on the hinder edge of the propodite in the legs of the third 
pair, the endopodite of the last limb of medium width or 
rather narrow, and the telson usually long, never very short.” 
Three out of the six species are from deep water. 
Species : 
Type. C. secura, Lanchester, 1902. P. Z.S. 1901. I. 
C. amboinensis, de Man, 1887. Arch. Naturges, lili. i. I. 
C. cecigena, Alc. & And., 1894. J. As. Soc. Bengal, Ixiii, I. (deep 
water). 
C. Dees Ale. & And., 1899. Ann. & Mae. Nat. Hist. (7) iii, 1 
(deep water). 
C. rotundicaudata, Stebbing, 1902. South African Crust. ii. 8. 
P C. goniophthalma, Rathb., 1900. Proc. U.S. Nat. Mus. xxiv. H. (deep 
water). 
Subgenus Curramus *, Bate, 1888. 
Definition: “Species of Callianassa with the maxillipeds 
of the third pair narrow, a lobe on the hinder edge of the 
propodite on the legs of the third pair, the endopodite of the 
last limb of medium width or broad, and the telson long.” 
Species : 
Type. C. subterranea (Mont.), 1808 t. Tr. Linn. Soc. ix. A. 
C. pachydactyla, A. M.-Edw., 1870. Nouv. Arch. Mus. vi. C. 
* This name cannot be used for any genus which contains C, sub- 
terranea, a8it must then be replaced by Callianassa on the ground of 
priority. As a subgeneric name it holds good. 
+ The true C. subterranca is a species which keeps both the primitive 
