A DECEPTION DETECTED 107 
hensile, thus making six pairs of legs, with a structural 
arrangement as regards three of them that would be unique 
among the Brachyura. At each date the species is said 
to come from the Isle of Guadeloupe. Leach rightly per- 
ceived that error and confusion were lurking somewhere, 
if it should not rather be said that they are conspicuous 
on the face of the two discordant accounts. Milne- 
Edwards in 1837, though with a confession of great un- 
certainty, institutes tor the smgle genus Pactolus the tribe of 
the Pactoliens, which he places among the Anomura. But 
soon after, in 1839, de Haan with great acuteness ob- 
served, ‘ Pactolus, Leach, Zoological Miscellanies, vol. ii. 
tab. 63, seems to me to be made up of the thorax of a 
female Leptopodia sagittaria, to which the legs of some 
other animal have been united; for the thorax of Pactolus, 
just as also the rostrum and abdomen, agrees with the 
female Leptopodia. The unlikeness in colour between the 
legs and the thorax in the figure referred to at once 
reveals the deception. Never are two alien forms found, 
agreeing exactly in the thorax, yet so disagreeing in the 
legs.’ The principle here enunciated is worth remembering, 
as in some parts of the world there are dealers who delight 
and find profit and have also great skill in fabricating mon- 
strosities, sometimes such as have deceived the very elect. 
Nearly related to Inachus is the gigantic Macrocheira 
Kampferi, de Haan, 1839, of which mention has been 
earlier made. In Japanese it is called the insular crab. 
Huenia is another genus of this family instituted by 
de Haan in 1839. The name refers to the acutely trian- 
gular form of the carapace, and is derived from the Greek 
word wyes, a ploughshare, a derivation which would have 
been hard to guess, had not de Haan obligingly mentioned 
it himself. At the foot of his plate 23 he names the 
figures ‘4. Masa (Huenia) elongata n. 5. id. variet. 6. 
Masa (Huenia) heraldica n.’ But the species established 
in the text is Mvja (Huenia) proteus. The double generic 
name results from the inconvenient practice, still some- 
times followed, of splitting a genus up into sub-genera. 
Sub-genera, if they are worth anything, are pretty sure to 
