60 STALK- AND SESSILE-EYED CRUSTACEA 
Eyes rather large. Antennx with the peduncle more or less cristate, 
the first joint of the external antenne short, not reaching the margin of 
the carapace. Hands broad, depressed. Tarsi of the ambulatory legs 
short, rather robust, with a single claw. 
This genus is particularly well represented on the Pacific shores of 
America, and affords an interesting proof of the affinity of the New 
Zealand Crustacean Fauna to that of those regions, 
Sub-Genus I, PETROLISTHES. 
Sides of the rostrum entire. Lateral margins of the carapace with 
only a single post-ocular spine, or smooth. Anterior legs with the arm 
and hand broad, of moderate length; arm usually with teeth on the 
anterior margins. 
65. Petrolisthes elongatus. 
Porcellana elongata, M. Edw. Hist. Nat. Crust. ii, p. 251, (1837) ; 
White, Dieffenb. New Zealand i, p. 265, (1843). 
Petrolisthes elongatus, Miers, Zool. Erebus and Terror, Crust. p. 8, 
pl. mi, fig. 3, (1874). 
Carapace faintly granulated, gastric region with two slight elevations, 
and separated from the rest of the carapace by a well marked groove, 
lateral margins of the carapace thin and sharp, front triangular, entire, 
but slightly inclined, very prominent, with a deep median groove. 
Anterior legs large, posterior margin of the wrist with two or three 
spinous teeth, anterior margin with a very obtuse tooth at the base of 
its front margin. Colour reddish-yellow. Length ¢in.; breadth 3 in. 
(M. E.). 
New Zealand (Heller; Coll. Mus. Paris; Brit.); Bay of Islands 
(Dana). 
" 
This species also occurs, but rarely, on the Australian Coast. It is 
apparently a very common species in New Zealand. 
Sub-Genus II]. PrTROCHELES. 
Petrocheles, Miers, Ann. Mag. Nat. Hist. (ser. 4) xvii, p. 222, 
(1876). 
