14 DE. W. T. CALMAN ON A COLLECTION" OF 



PsETJDOZius DISPAE, Dana. 



Pseudozius dispar, Dana, U.S. Expl. f]xp., Crust, i. p. 235, pi. xiii. fig. 9. 



Sphmrosius dispar, Stimpson, Proc. Acad. Philad. 1858 (1859), p. 35. 



Pilumnns nitidus, A. Milne-Edwards, N. Arch. Mus. Paris, ix. p. 249, pi. x. fig. 2 (1873) ; De Man,. 



Arch. Naturg. liii. (1) p. 305 (1887). 

 Pseudozius dispnr, Ortmann, Zool. Jahrb. Sj'st. vii. ]). 433 (1893). 



Two sj)ecimens, the larger of whicb, an ovigerons female, differs somewhat from 

 Milne-Edwards's figure as regards the outline of the carapace. The antero-lateral margin 

 is considerably shorter than the postero-lateral. The greatest width is in the line 

 of the penultimate antero-lateral teeth and well in front of the middle of the length. 

 In the figure the greatest width is at about the middle at the level of the last pair of 

 antero-lateral teeth. The description given by De Man applies accurately, in most points, 

 to our specimen, except as regards the supposed sexual difl"eronces. He found the 

 carapace narrower in a male specimen, the breadth-ratio being only 1"25 as against 1-37 

 in the female; and in the male the outer surface of the large hand was smooth with only 

 a few granules near the proximal end, while in the female the whole surface was covered 

 with granules as in the smaller chela. The latter difference between the sexes was also' 

 found by Ortmann. As regards tlie breadth of the carapace, our sjiecimen is intermediate 

 between the two examined by De Man, the ratio being I'Sl. The measurements given 

 by Milne-Edwards have evidently suffered from some misprint, but measurements takea 

 from his figure of an adult male give a breadth-ratio of 1"41, considerably greater than 

 that given by De Man for the female. As regards the granulation of the large cheliped, 

 our specimen presents exactly the condition figured by Milne-Edwards and described by 

 De Man as characterizing the male, the outer surface being smooth with a few granules 

 grouped near the proximal end. Our second specimen, a minute and immatm-e female. 

 Las more numerous granules on the large chela, which, however, is still much smoother 

 than the small chela. In both cases the right cheliped is the larger. 



De Man suggested the possible identity of Milne-Edwards's species wiihihe Fseudozius 

 dispar of Dana, and this suggestion has been accepted by Ortmann. Dana's figure is 

 very similar to our specimens, and his description, though lacking in detail, applies 

 perfectly, save in the one point that the finger of the large hand is said to be " smooth 

 and round, and not channeled." In our specimens, as in De Man's account, the fingers 

 of both hands are grooved. Dana gives the breadth-ratio of the carapace as 1-21, rather 

 less than the narrowest individual examined by De Man. The table of generic characters 

 given by Dana [1. c. p. 229) states that the carapace in this genus is " fere planus " ; but 

 that this does not apply to the species in question may be gathered from the fact that 

 Stimpson refers it to his genus SphcBrozius, which is defined as having the body sub- 

 globose. Stimpson, however, gives as a generic character " Margo frontalis et supra- 

 orljitalis continuae nee sinu nee incisura separataD." In our specimens, as in De Man's 

 description, the frontal lobes are separated fi'om the supraorbital margin by a slio-ht but 



