MONOGRAPH OF THE LEUCOSIADAR. 309 
Species unica, NURSILIA DENTATA, mihi (Tan. XXXIV. fig. 6). 
Hab. in oceano Indico. Mus. Brit, 
Carapace rather broader than long, the margin laminated ; a slight fissure between the 
hepatic and branchial regions, an obtusely triangular tooth on the margin of the former, 
and three slight angular projections on the latter; several small projecting teeth on the 
surface of the carapace, and a longitudinal carina, on the posterior half of which are three 
strong spines curved forwards; an elevated line on the branchial region. External foot- 
jaws extending forwards to the frontal margin, meeting only at the apex, and leaving an 
interspace, the posterior part of which is filled by the last joint of the abdomen. The 
anterior legs are long and slender, the hand tumid on the proximal portion; the fingers 
longer than the hand, very slender, curved at the extremity, and finely toothed. The 
abdomen of the female extremely convex, the terminal joint somewhat triangular, and 
extending forwards between the base of the foot-jaws. 
A single specimen, a female, is in the British Museum. 
Genus ARCANIA, Leach. 
Cuar. GaN.— Testa globulosa, spinis seu tuberculis elevatis plurimis armata. Orbita suprà et extrorsum 
aperta. Fosse antennarie longitudinales. Pedipalpi externi caule exteriore recto, lineari, apice 
interiore emarginato-truncato ; caule interiore gradatim acuminato. Pedes antici gracillimi. Abdomen 
Manis lanceolatum, segmentis a tertio ad sextum vel ad quintum coalitis. 
This genus is closely allied to Zphis, from which it differs in the more globular form of 
the body, in the number and character of the spines with which it is armed, and in the 
form of the external foot-jaws. 
ARCANIA ERINACEUS, Herbst. Corpore atque membris dens? spinosis, spinis spinulosis. 
Cancer Erinaceus, Herbst, t. 20. f. 111. 
Leucosia Erinaceus, Fabr. Suppl. p. 352. T 
Arcania Erinaceus, Leach, Zool. Miscell. iii. p. 24. Edw. Crust. ii. p. 134. 
Hab. in mari Indico. Muss. Brit., Soc. Linn., Bell. 
A well-known species, figured by Herbst and by several subsequent authors. It differs 
from other species in the numerous spines with which it is armed, and in the spines being 
themselves spinulose. 
ARCANIA UNDECIM-SPINOSA, De Haan. “ Thorace spinuloso, spinulis a wir 
11-spinoso, spinis acutis simplicibus; brachiis granulatis, digitis manibus longio 
ribus." 
. De Haan, Crust. Japon. p. 135. t. 33. f. 8. 
Hab. in Japonia. 
«horace levi, granuloso, marginibus 
| | ite. 
ARCANIA NOVEM-sPINOSA, Adams and Whi ibus spinis duabus, posteriore spiná 
- latero-anterioribus spinis duabus, — LÀ 
: longä recta.” 
| i of the Samarang, p. 56. t. 13. f. 1. 
Iphis novem-spinosa, Adams and White, Crust. of the Voyage sae 
