VI 



PAGURIDEA LITHODES MAIA 



1/7 



reduced and carried tightly Hexed on to the ventral surface of 

 the thorax. They live a free, unprotected existence, and are 

 highly calcified. They are, however, certainly Pagurids, as is 

 evidenced by a number of anatomical characters, bxit most 

 clearly by the asymmetry of the abdomen, especially in t lu- 

 ll-male, which is not only markedly asymmetrical in the arrange- 

 ment of its dorsal plates (Fig. 121), but also in the presence of 



[.[,,. 121. _ Lithodes maia, 9, in ventral view, x . The abdomen is Hexed on the 

 thorax, so that its dorsal surface is seen. 1.3, Lateral plates of third abdominal 

 Moment : !.'>, left lateral plate of lil'tli alulominal segment ; in, marginal plate : '/'. 

 brush-like last pereiopod ; Te.6, telson and sixth abdominal segment. 



three pleopods upon the left side only, as in ]'>ir<jn. The male 

 is without these appendages, and the sixth pair of pleopods is 

 aljsent in both sexes. The remarkable caleilied pl;iies upon the 

 abdomen bear a superficial resemblance to those in Birgus, Imt 

 their evolution is traced, not from a (Vnobite, but from ;in 

 Eupagurine stock. 1 



In some of the. Kuiiao-urinae, e.g. Pylopagurus, teelily r;ilnlie.[ 

 pliites ;ire present upon the segmenis of the abdomen 

 (Fig. 1-2-2, A). 



In the most primitive of tin- Liihodida.- we witiies 



1 Brandt, Jinll. ri,,js. Mull,. Ac,,,!, si. Pttersbourg, i. ]>. 171, md viii. p. 

 Boas, A'. Dansk. Vid&nak. Xc/.s/.v,/,. Skrift. Naturwd. og Math. Afd. 6, lid. 'J, 1- 

 Bouvicr, Ann. .sv/. +\,it. (Zool.} (7) xviii. p. 1:")7. 



Vi H,. IV 



