Thomson. — On New Zealand Crustacea Anomura. 191 



The basal joints of the auteunules are furnished with 

 numerous short teeth on their outer edges, and are visible 

 from above in front of the carapace. 



Eye-peduncles with one or more short spines. 



Outer maxillipedes with the third joint spinose on the 

 outer margin. 



Chelipedes with a nearly square meros ; carpos with the 

 upper margin rather thin, crest-like, and obscurely toothed 

 (a prominent ridge is sometimes present on the outer side), 

 and the lower margin has three more or less defined teeth. 



Ambulatory feet with the meros scarcely dilated, and with 

 only a few scattered hairs on the upper edge of the carpos and 

 propodos ; dactylos rather elongated. 



Size: Length of carapace, 8mm.; breadth of carapace, 

 7'5 mm. ; breadth between tips of the carpi of the chelipedes 

 (fully stretched), 15 mm. ; length of antennae, 16mm. 



Habitat. — Cook Strait and Stewart Island (Filhol) ; Wa- 

 nganui {S. H. Dreio) ; Lyttelton, dredged {Chilton) ; Blueskin 

 Bay, trawled, and Bay of Islands, dredged in 8 fathoms ; 

 Akaroa, dredged in 6 fathoms (Suter) ; New Brighton, from 

 roots of Macrocystis (Suter). 



This is evidently not a shore-living species, though 

 apparently common in shallow water. There is a great deal 

 of variation in the extent to which the spines are developed 

 on the sides of the carapace and the chelipedes. The largest 

 specimens seem always to be the smoothest, and the smaller 

 ones more spinous. Considering how great the range of this 

 variation is among my specimens, I cannot recognise any 

 sufficiently distinctive character on which Filhol can separate 

 his P. steivarti. 



Some of Suter's New Brighton specimens have the limbs 

 very roughly granular. 



Genus 2. Petrocheles, Miers. 



1876. Petrocheles, Miers, Ann. Mag. Nat. Hist., ser. 4, xvii., 



p. 222. 

 1876. Petrocheles, Miers, Catal. N.Z. Crust., p. 60. 



Carapace subovate, depressed, slightly longer than broad ; 

 front triangular and with its sides spinose ; lateral margins 

 with a series of spines. Chelipedes elongated, slender, with 

 a series of spines on the anterior margin of the carpos. 



The distinction between the two genera — Petrolisthes and 

 Petrocheles — is a very trivial one, and Miers only classes 

 them as sub-genera. 



Petrocheles spinosus, Miers. 



1876. Petrocheles spinosus, Miers, Ann. Mag. Nat. Hist., ser. 4, 

 xvii., p. 222. 



