A. E. V err ill Decapod Crustacea of ]!> n/mda. 



Two specimens of tins species were taken in shallow water, in a 

 sandy cove of Castle llarlmr. near \\"al^iii--liain Hay, in .March, I'.MI| 

 (coll. A. II. Yen-ill, Yale Mils. ). Cast -off shells were found else- 

 where, of larger si/.e. Bahamas, six fatlioins, and Porto Kico 

 (Rathbun). 



The Pacific form ranges from the (lull' of California to Panama 

 Cape St. Lucas i St imps, m, coll. Xanliis, Y;ile Mils. ). I 'ana ma | ( 'a pi . 

 Y. Dow. Yale Mns.). 



HAPALOCARCINIDEA, HOT. 



The position of the family HapalocarcinidcB in the system seema 

 to be decidedly doubtful. Stimpson thought his ._.,. nu^ \ v; is mosi 

 nearly related to the < Jrapsoid-. 



Heller placed his genu<, < '/>//>'<>'/, //*/.--, next to the /'>'///>!/,, //'/,/ . 

 Miss L'athbun (Crust. IIa\v. Is., I;HM;) placed the family at the end 

 of the Oarystomatdi in proximity to the J>n/-;/,/>/'</<i (/,'/// //.sw, etc.), 

 to some of which tin-re is coiiH<lerab|e res,.|iill:iiii-e. 



On the whole, it seems t" me best to consider it as constituting ; , 

 peculiar superfaiaily group, in which the genera are highly spec- 

 iali/ed, so as to adapt them to the peculiar halnt of li\iii'_; in cavitie-. 

 dens, or ^alls in the living jmrts of corals. 



Kach species hitherto discovered appears to represent a distinct 

 -elms, the genera ditt'crin^ ainon-- themx-lves widely in structure. 



In general form and habits they superficially resemble some of the 

 Aiionii'i-n, especially the females, which ha\ e a lar^e, elongated ahdo- 

 men, in the form of a pouch, with all the sutures distinct, but not 

 capable of curling up closely beneath the thorax, but there are no 

 appendages on the sixth segment. The abdomen of the males is 

 narrow and is applied closely to t he sternum, as in ordinary IJrachyura. 

 The epistome is feebly developed; the buccal area is lar^e and 

 arched anteriorly. The lower border of the orbit is little developed. 

 The outer antenna- are small and e.xtraorbital. The antennules have 

 a laru'e. prominent basal joint. The carapace is narrow and more or 

 less oblong, or seinicylindncal, not much narrowed anteriorly. The 

 front is usually subtrnncate or emarginate without a central tooth. 



The outer maxillipeds are separated at base by a sternal lobe ; 

 they have the ischium broad, often with a convex inner lobe ; the 

 menus is small, seated well back, with the palpus articulated in a 

 notch of the inner edge ; the exognath is small. 



The chelipeds are feeble, often little if any larger than the next 

 legs ; the chelte are simple, with acute tips. The ambulatory legs 



