MONOGRAPH OF THE LEUCOSIADA. 805 
PHLYXIA LAVIS, mihi (Tas. XXXIV. fig. 3). Brachiis triedris; test’ levi, margine 
laterali unidentato. 
Hab. ad Novam Zealandiam. Mus. Brit. 
Carapace rhomboidal, smooth, rostrum obtuse, slightly emarginate; margin of the 
branchial region with a single minute tooth, posterior margin with three obtuse teeth ; 
anterior legs not twice as long as the carapace; arm three-sided, triangular, granulated ; 
hand half the length of the arm, smooth, slightly carinated on the outer side, fingers 
hardly deflexed. | 
Length of carapace 0*4 in. : 
The generic characters are much less strongly marked in this species than in either of 
the others, but the form of the foot-jaws, the three teeth on the posterior margin of the 
carapace, its rhomboidal form and other points of structure, sufficiently show its close 
relation to them. It may be considered perhaps as osculant between this genus and 
Ebalia. 
i Genus LITHADIA, Bell. 
Testa rhomboidea, rudis, regionibus gibbosis, rostro bifido, resupinato terminata. Orbita supra et extror- 
sùm aperta. Fosse antennarie oblique. Pedipalpi externi caule exteriore ensiformi, antice obtuso ; 
interiore lanceolato, exteriore longiore. Pedes antici robusti, rudes; brachiis tuberculatis, ad 
marginem exteriorem cristatis; manibus cristatis, digitis approximatis. Abdomen Maris segmentis 
tertio, quarto et quinto coalitis; Fæmınæ — ? 
The grounds upon which I have thought it necessary to assign a distinct generic rank 
to the species to which the above characters belong, closely allied as it is to Ebalia, are 
the extremely different general aspect of the whole animal, arising from the rough and 
strong prominence of the different regions, the projeeting spines, the large and prominent 
granulations, so unlike any other form in this family, excepting Oreophorus, and some 
distinct though not very striking differences in the form of the external foot-jaws, the legs, 
and particularly the abdomen in the male. 
Species unica, Lrruapra Cumrner, mihi (Tas. XXXIII. figs. 6, 7). 
` Hab. ad oras America centralis (Puerto Portrero). Mus. Bell. ponte 
Carapace very strongly marked by rude elevations, sharply circumscribing deep 
hollows. In the younger specimen of the two in my possession, the elevations are more 
numerous and distinct, and the sulci separating them are continuous; the difference 
in the older specimen arising from the confluence of several of these Edi with 
the sulci become merely four irregular ‚eireumseribed ue tooth; posterior 
distinct granulations*. Posterior branchial lobe forming & EU a o eacgipate. 
lobes of the cardiac region similarly modified. 2 ` En species ^ not other 
* This difference is so remarkable, that the venue ee dei some ordinary law of variety. The 
instances of similar variations in the surface, ei m 
ite separate, and are distributed very 
tubercles, for example, which in the normal form of Eurynome aspera are que 
uall en mi few tabulated surfaces ; and 
wpe tin pa - nally more or less confluent, forming a 
eT distinctl the carapace, are occasionally der rame 
it has fi d E ARTE by Risso as a distinet species, under the name of Eu. scu = a specimens 
exhibiting intermediate states. 
