150 



MKKISTIC VARIATION. 



[PART I. 



limbs of tin.- two side^ ; that the exopodite of the right side is 



A 



I! 



Fn.. is Cancer ii,inms tin- right and left third maxillipedes, that of the 



; -i.l.- having t!,. endopodite in tin- likmt-ss of the endopodite of a chela. 



/./.. ba.-n :i]i.. j,,,,lit' ..//). ilai-tylopodite, ep. cpipodite, g. groove between 



part- n |>n -. iitinr isrhi..]iuiiite and meropodite, </'. groove representing the suture 



lit which a normal cli.-la is thmwn olT it injured. From P. Z. S., 1890. 



niially like that of the left, but that it lacks the inner process 

 and the tii-'-lluni \\hich an- borne by the normal part. There was 

 some indication that this branch of the limb had been injured, and 

 perhaps tin- tlagellum may have been torn away, but the appear- 

 ances \\vn- not Midi as to warrant a (-(inclusion on this point. The 

 braiirhial .-].ipo.liti-s (not shewn in the figures) were normal in 

 both cases. Tin- rnd<>p<nlite of the right side was entirely peculiar, 

 and was in tact, literally transmuted into the likeness of one of 

 the great chela?. It consists of a single joint (ntl), articulating 

 with the basipodite centi-ally and bearing the carpopodite. This 

 >in-le joint repi-esents, as it were, the ischiopodite and meropodite 

 of an ordinary chela, but these two parts are ankylosed together 

 and the articulation between them is only represented by a groove 

 i //). Another groove (f/') represents the groove upon the ischiopo- 

 dite of the chela, at which the limb is commonly thrown off by 

 tin- animal if it is injured. The carpopodite, propodite and dactylo- 

 podite are freely mi >\ cable on each other and hardly differ, save 

 in absolute si/e, from those of the normal chehe. The shape, pro- 

 portions and texture are all tho>e of the chela. B.VTESOX, W., 

 Proc. /,/. Nor., 1MM). p. :,.s(i, fig. 1. 



SO. A similar case 1 of ('<n,,-i r ji<iitrnt< $. 4 inches across carapace, 

 mature, right pcdipalp [i.e. 3rd maxillipede] normal, left pedipalp 

 modified into a chela having all the joints clearly defined, CORNISH, 

 T., Zoologist, S. :}, vni. p. 349. 



*S1. Palinurus penicillatus. The left eye bearing an antenna- 

 like tla^ellnm, growing up from the surface of the eye as shewn 

 in the figure (Fig. lit). The eye-stalk and cornea, as represented, 

 appear to h.u,' hren of the normal shape but reduced in size. 



1 Similar cases since published by lln IIAKD, Ann. Sci. X,it., Zool., 1893. 



