30G RECORDS OF THE AUSTRALIAN MUSEUM. 



The following notes and the accompanying plate show the 

 great range of variation in the characters, usually relied upon to 

 differentiate the species of this genus, as presented by a splendid 

 series of C. spinosvs from Cape York, N. Australia. 



The gastric region may be strongly convex or flattened, and 

 the width of the front varies between 3 and 3*5 in the length 

 of the carapace. The length of the eyes is also variable. The 

 hand of the larger cheliped may be intensely spiny, or the lower 

 portion of the outer surface may be perfectly smooth, and a more 

 or less distinct stridulating ridge on the upper part may be 

 present or absent. The propodus and dactylus of the second and 

 third, or third only, pairs of left legs may be sub-cylindrical and 

 long, or markedly flattened and shorter. If flattened, there is a 

 prominent ci'est on the upper and lower posterior margins of the 

 dactylus, and sometimes also on the distal portion of the propodus. 



Great as these variations seem, they are certainly within the 

 limits of the one species, as I found all my specimens living together 

 under a sheet of bark at Cape York, and they form an unbroken 

 series between the two extremes I have figured. Further, 

 though they would suggest that the variations are due to the age 

 of the individuals (young, variabilis; adult, spinosus), other 

 specimens in the Museum collection from the north-west coast of 

 Australia, Murray Islands, Torres Straits, the Fiji Islands, and 

 the New Hebrides show that this supposition is incorrect. 



As Birgus hirsutus, Hess has recorded this species from Sydney. 

 This is, however, certainly wrong, as the genus is confined on the 

 eastern coast of Australia to North Queensland. For the same 

 reason, Heller's record 1 of C. rugosus, M. Edw., from Sydney, 

 is incorrect. 



Leander serenus, Heller. 



(Plate lxxxix., figs. 9-12.) 



Leander serenus, Heller, Reise Novara, < 'rust., 1865, p. 110, pi. x., 

 fig. 5. Id. Haswell, Cat. Austr. Crust,, 1882, p. 195. 



Palcemon affinis, Bate, Chalk Rep., Zool., xxiv., 1888, p. 782, 

 pi. exxviii., fig. 5 (nee. l\ affinis, M. Edw.). 



Carapace smooth and polished. The rostrum is very variable 

 in shape, being either broad or narrow, and its upper margin may 

 be almost straight, or else bent upwards towards the tip. It is 

 armed with six to nine nearly equidistant teeth above, and three 



teller— Keise Novara, Crust., 1865, p. 82. 



