8 DK. W. T. CALMAN ON A COLLECTION OF 



to A. Buppellu in the British Museum collections, but iu none of the latter are the hairs 

 quite so long as in our largest individual. 



Localities. '• Murray Island " ; " Thursday Island, fringing reef and shore " ; "Albany 

 Passage, 10 fath." 



ACT^A CALCITLOSA (Milne-Edwards). 



Cancer calculosvs, H. Milne-Edwards, Hist. Nat. Crust, i. p. 378 (1834). 



Actma calculosa, A. Milne-Edwards, N. Arcli. Mus. Paris, i. p. 276, pi. xviii. fig. 3 (1865) ; Haswell, 



Cat. Aiistr. Crust, p. 45 (1882). 

 Euxanthus tuberculosus, Miers, Crust. ' Alert,' p. 205, p. xix. fig. A (1884). 

 AcUea calculosa, Henderson, Tr. Linn. Soc. London, (2) Zool. v. p. 356 (1893) ; Alcock, Journ. Asiatic 



Soc. Bengal, Ixvii. (2) p. 152 (1898). 

 Pive specimens of this species are in the collection. Prof. E. L. Bouvier has very 

 kindly taken the trouble to compare one of our specimens, sent to him for the purpose, 

 with the original type specimen of H. Milne-Edwards's Cancer calculosus in the Paris 

 Museum. He writes as follows : — 



" J'ai compare minutieusement votre Crabe avec le type 6.'Actcea calculosa, Edw. II 

 appartient evidcmment a la meme espece. Les tubercules du test y sont beaucoup plus 

 saillants, mais ils sont partout disposes dans le meme ordre et sont entoures aussi 



d'une aureole peripherique de ponctuations je vous le repete, on ne saurait douter 



de I'identification." 



The identification of our specimens being vouched for on such excellent authority, it 

 may be usefiil to give in some detail their characters as compared with Aetata granulata 

 (And.), since it appears that recent writers have not always successfully distinguished 

 the two species. 



The breadth-ratio of the carapace varies from 1-33 to 1-4 without apparent relation to 



the actual size. The three posterior lobes of the antero-lateral margin are prominent 



and well-defined, and in front of these the first lobe is represented by a single tubercle. 



In Actma ffranulata * the lobes are low% rounded, and indistinctly separated. The regions 



of the carapace are much more distinct in A. calculosa, being separated by rather deep 



grooves, which are in part smooth and free from granules. There is a marked and 



generally smooth groove parallel to the hinder margin of the carajoace and separated 



from it by two or, in one case, three rows of granules. The posterior margin is defined 



at each end by a small spiniform tubercle which is not distinct in A. (jranulata. The 



cardiac area is of a rather different shape from that shown in the figure given by 



A. Milne-Edwards, being produced and much narrowed anteriorly. The tubercles on the 



surface of the carapace are rounded, smooth, and surrounded each by radiating puucta- 



tions. On the posterior part of the carapace in some specimens they become depressed 



and confluent. In A. granulata the tubercles are more pointed and the radiating 



* I have used lor comparison two specimens of A. <jranulata from Japan in the Museum of University CoUege. 

 These diifer slightly from Savigny's figure (l)escr. de I'Egypte, Crust, pi. vi. fig. 2) in the rougher appearance of the 

 carapace, but they iseem to agree in all essential points with this as well as with the descriptions of later writers. 



