466 MK. L, A. BORRADAILE ON CRUSTACEANS [June 7, 



resemble it iu this respect. In P. margiaatus Stimpsou the 

 jiumber tends to incre<ase. P. hellis Heller, P. speciosus Dana, 

 P. haswdli Miers, P. dentata H. M.-Edw., and P. rw/escens Heller, 

 have at least tour. 



The spines on the upper edge o£ the merus of the walking-legs 

 are another character which it has been attempted to use as specific. 

 They are, however, so inconstant, and form such a complete series, 

 from specimens with an almo:<t straight edge (Plate XXXVI. fig. 1 a), 

 through those with imbricating scales, to those with well-marked 

 spines, that it seems impossible to make use of them. The best- 

 marked of these spines is about a third of the length from the far 

 end of the joint (fig. 1 h). Often this spine appears on one or a 

 few legs only, and as often as not the legs of the two sides do not 

 agree. In Leach's original specimen of P. asiaticus in the British 

 Museum, the lirst two walking-legs on the left side alone show 

 spines. The type specimen of P. lamarclcii is without them. 



Then there is the epibranchial spine, whose presence or absence 

 would seem to afford an excellent criterion for our purposes. 

 According to Ortmaun, however (Semon's ' Forschungsreisen in 

 Austral.' loc. cit.), this is not of specific value, since it occurs in 

 specimens from the same locality as, and in other respects exactly 

 resembling, forms without such spines. 



Ttie breadth of various joints of the limbs varies, but is not to 

 be relied upon, since it appears to alter with age. 



Lastly, I have ventured to name a new yariety, Jimbriatus, from 

 the fact of its possessing a more or less plentiful fringe of hairs 

 to the outer margin of the " hand " (Plate XXXVI. fig. 2). 



The following key indicates the characters attaching to those 

 varietal names which it appears advisable to retain : — 



A. With an epibranchial spine. Colour tenda to sprinkling of red spots on 



lighter ground. 

 i. Without a fringe to the outer side of the chelse. 



1. Without spines on the anterior margin of the merus of any walking- 



leg r^?;c (Leach), 1820. 



2. With at least one spine on the anterior margin of the merus of at 



least one of the walking-legs. Usually with spines on several legs. 



Var. asiaticus (Leach), 1820. 

 ii. With a scanty or plentiful fringe to the outer side of the chela. With or 

 without spines on the anterior margins of the walking-legs. 



Var. fiiubriatus, nov. 



B. Without an epibranchial spine. Colour tends to red or white with large 



blotches of purple or blue. Attains a lai-ger size tlian (A), has a greater 

 aver;\ge of teeth on the inner margin of the wi-ist, but none on the merus 

 of any walking-leg. Exhibits its peculiarities in small specimens, and is 

 therefore not merely a collection of older individuals. Possibly a distinct 

 species Var. n/fescais (Heller), 1861. 



1 should have used Milne-Edwards's name of dentatus for this 

 latter form, since his definition would agree very well with the spe- 

 cimens, but de Man states very positively (Zool. Jahrb. ix. p. 374) 

 that he has had the original specimens sent him from Paris and 

 that they possess an epibranchial spine. Should there not be, ns 



