PORTUNHXK. 



POBTPNIDJa, 



k BBMJSS with the lot tooth of the Utero-anterior border of the 

 carapace at least twioe as large M tht preceding. 



b. Median teeth of tb. front much mot* projecting than the lateral 



. , 



L SAa (Caxxr Mnmu mltformit, Seba, 'Mus.. 1 iii., pi SO, , 

 oopisd bv Lalrrille, in ' KncycL,' pi. 272, , under the name of 

 Pmttuxu MMpMnpinifiu). Sue nbout the lame as L. ynututala. A 

 native of the ooaU of llnuuL (Milne-Kdwarda.) 



U. Median teeth of the front leei projecting than the others. 



M*. Hand* large, of the ordinary form, and shorter than the 

 transversal diameter of the carapace. 



L fcutata (CWrr kattalm, Linn. ; Porttanu hatlaltu, Latr. ; Lni>a 

 lt/onrii, Deem.). Length about two inches. It ii a native of the 

 Mediterranean. 



W**. Hand* filiform and of great length, being nearly one and a 

 half Oi* Iran renal diameter of the carapace. 



L Fortfft (iMpa J-'orcti-t, Leach ; I'or1*niu Poretpt, Latr.). Length 

 about an inch. It it a native of the Antilles. 



(Utr.). Carapace In moat of the specie* characteristic; 

 but in some it gradual); approximate* to that of the Lttpter ; in fact, 

 sometime* it ha* the form of an elongated square; iu transversal 

 diameter i* nearly double the length, and its frontoorbiul bonier form* 

 with the Uttro-enterior border* a nearly right angle ; in other cases it 

 is nearly hexagonal, iu six border* form nearly equal angles, and iu 

 width only exceed* about half of it* length. The front i* always very 

 wide, projecting, and at least a* much advanced a* the inferior border 

 and external angle of the orbit, a disposition which is never observable 

 in the Lnpta. The latoro-anterior borders of the carapace are more 



or Uas obliaue, but alway* form with the fronto-orbital border a very 

 angle, where there are from four to seven teeth, the 

 which is never remarkably larger than the othen. The eyes 



strong marked 



Us* o? which i . 



are stout and abort; the orbit* oval, and completely separated from 

 the antannary foseeta ; the upper border of the latter present* two 

 mall Ossures, and their angle U often nearly as distant from the 

 inr.lian line a* the angle which terminate* behind Uie Utero-anterior 

 The internal antenna? bend back completely in their fo<*eU, 



border. 



and the inter antennary partition projects but little. The banilnry 

 joint of the external antenna; is in general very wide, and alway* 

 soldered to the front throughout the whole extent of it* anterior 

 border, presenting externally a more or lew considerable projection 

 which separate* the orbit from the point of articulation of the mov- 

 able stem of those appendages, and which is very long, and inserted 

 oBHtimsmi very far from the orbital cavity. The cpiatome is very 

 distinct and of a losenge-shape. 



M. Milne-Edwards divides the genus into the following sections : 



1. Pronto-orbital border not occupying more than two-third* of tlio 

 width of the carapace, and forming a rather open angle with 

 the Utoro-ejiterior borders, which are armed with six or seven 

 Ueth. 



Hexagonal Tkalamiltt. 



i Frontoorbital border occupying nearly the whole width of the 

 carapace, and forming a nearly right angle with the latero- 

 anterior border*, which are armed with four or five teeth. 

 Quadrilateral Thalamil.r. 



The Utter form the fint submenus in M. Milne-Edward*'* arrange- 



. Species having the front entire or divided into lobe*, but with 

 no teeth. 



T. Ckaptalii (Porlmvt Cliaplalii, Aud., ' Cnut Sav. Kgypte.'). 

 Length about an inch. It i* a native of the Bed Sea. 



nalamita Chaplain. 



b. Species whose front is armed with deeply cut and flattened teeth. 

 T. crcnata (Portunut crenatui, Latr.; Thalamita Atlmde, Querin 

 ' Icon. Cr.,' pL 1, f. 4). 



2nd Sub-Qenus. Hexagonal Thalamilir. 

 a. Species having the latero-antcrior border of the carapace armed 



with six teeth. 



a. Last lateral tooth nearly the same size as the preceding. 

 a*. Anterior feet armed with spines, but without elevated granu- 

 lations. 



T. cntcifera (Portunut eruciferut, Fabr. and Latr. ; Cancer 

 tatiu, Herbal I). Length from three to four inches ; colour reddish 

 with yellow spots and bands, the median markings resembling a cross 

 Found in the Indian Ocean. 



a**. Anterior feet presenting between the spine* with which they 

 are armed, a great number of tubercles or elevated granu- 

 lations. 



T. Xatator (Cancer Kataior, Herbst; Portunut lanyuinolcntut 

 Bosc,). Found in the Indian Ocean. 



nalamit* Kalalor. 



