Classification of the Thalassinidea. 539 
PA. nodulosus (Meinert), 1877. Naturh. Tidsskr. (5) xi. A. 
? A. Brocki (de Man), 1887. Arch. Naturges. liti.i. I. 
? A. Picteti (Zehntner), 1894. Rev. Suisse Zool. ii. I. 
? A. defensus (Rathb.), 1900. Bull. U.S. Fish Comm. E. 
? A. inequalis (Rathb.), 1900. hy 3 E. 
The species described by de Man in 1887 (Arch. Naturges. 
li. 1.) as Axius clypeatus should probably become the type 
of a new genus, with the following characters :— 
“Back arched in the fore part of the carapace, no keel 
behind the cervical groove, eyes well pigmented and with 
long stalks, and a small oval end-joint on the exopodite of 
the last limb.’ The gills are unknown. 
Genus Catocaris, Bell, 1853. 
Definition: “ Axiide with the body subcylindrical and the 
back arched, the cervical groove distinct, a toothed ridge 
extending backwards from each edge of the rostrum towards 
the cervical groove, which it does not meet, a third ridge 
running the whole length of the carapace in the middle line, 
the eyes almost or quite without pigment, an arthrobranch 
on the second maxiliiped*, no pleurobranchs, and a suture 
on the exopodite of the first limb.” All the known species 
live in deep water. 
Subgenera: Calastacus, Calocaris. 
Subgenus Carasracus, Fax., 1895. 
Definition: “Species of Calocaris in which the antennal 
thorns are of a good size.” 
Species : 
Type. C. stilirostris (Fax.), 1893. Bull. Mus, Harvard, xxiv. G. 
C. investigatoris (And.), 1890. J. As. Soc. Bengal, Ixv. I. 
C, felix (Ale. & And.), 1899. Ann. & Mag. Nat. Hist. (7) iii. I. 
C. longispinis (McArdle), 1901. cp . (7) vil. I. 
C. quinqueseriatus (Rathb.), 1902. P. U.S. Nat. Mus. xxiv. 4H. 
Subgenus Catocanris, Bell, 1853. 
Definition: “Species of Calocaris in which the antennal 
thorns are minute.” 
Species : 
Type. C. Macandree, Bell, 1853. Brit. Stalk-eyed Crust. A, B, I. 
C, Alcocki, McArdle, 1900. Ann. & Mag. Nat. Hist. (7) vi. I. 
Genus Scyroxertus, Gerst., 1856. 
[= Evaaius, Kingsley, 1882.] 
Definition: “ Axiidee whose back is arched in the fore part 
* Absent in C. stilirostris (?), 
