6 DE. ^Y. T. CALMAX ON NEW OE EAEE 



genus. It appears to resemble B. pidchella in the disposition of the ridges on the 

 carapace, though these are very obscure. 



Occurrence. — Gulf of Siam, "Koh Kam, 5 fathoms." 1"h, Mortensen Coll., Copen- 

 hagen Museum. Co-types in British Museum. 



Genus Cyclaspis. 



The new species described below form, with those already referred to this genus, 

 a somewhat varied assemblage, within which, however, I am unable to define any 

 groups which appear worthy of generic rank. The species of Cyclas])is form a very 

 important part of the Cumacean fauna of tropical and southern seas. 



Key to the Species of Cyclaspis 

 (excluding C. argus and C. lidriata Zimmer, of which I have seen no specimens *). 



A. No eye or ocular lobe C. longicaudata G . O. Sars. 



B. Eye aud ocular lobe present. 



a. Carapace quite smooth. 



a. Peduncle of uropods more than twice as long as the rami C. picta Caiman. 



h. Peduncle of uropods not much longer than the rami. 



A'. Basis of first legs with a spiniform tooth at its distal end. 



a'. First legs long, propodus twice as long as carpus . . . C. hornelli Caiman. 



b'. First legs short, propodus equal to carpus C. herdmani Caiman. 



B'. Basis of first legs without a spiniform tooth at its distal 

 end. 



a'. Carapace one-third of total length C. jmsi/la G. O. Sars. 



1)'. Carapace less than one-tliird of total length. 



1. First legs very long, basis about half as long as distal 



segments together C. longipes, sp. n. 



2. First legs short, basis nearly equal to distal seg- 



ments together C. kvis G. M. Thomson. 



b. Carapace more or less strongly ridged or sculptured, or armed 



with a tooth on the dorsal crest. 

 a. Ridges enclosing a quadrilateral depressed area on each side 

 of the carapace. 

 A'. T^vo strong transverse ridges crossing dorsal surface of 

 carapace. 



a'. Transverse ridges thickened C. exsculpta G. O. Sar.s. 



b'. Transverse ridges not thickened, the posterior one with 



two liooked teeth C. persailpta Caiman. 



* Tw.) additional species of the genus have been described by Dr. Zimmer since this paper was ivad 

 (Zool. An/,, xsxi. p. 367, 1907). 



