CASHIERING THE ANOMURA 133 



CHAPTER X 



TRIBE V. ANOMALA 



THE sternal plastron or breastplate is wide. The 

 branchias lie obliquely, and may attain the number of 

 fourteen pairs. The vulvae open not on the breastplate, 

 but in the bases of the third pair of legs. 



This tribe of Anomalous Brachyura has long been con- 

 sidered a division of a separate sub-order called the 

 Anomura, meaning Stalk-eyed Crustaceans ' with un- 

 symmetrical tails.' To this division the name Apterura 

 was given, to distinguish it from another division called 

 Pterygura. The first name signifies those that have 

 unwinged tails, the second those that have winged 

 tails. The wings referred to are formed by the ap- 

 pendages of the sixth segment of the pleon, which in 

 the Pterygura are expanded on either side of the telson, 

 but which in the Apterura are not developed By the 

 transfer of the latter division to the Brachyura its old 

 name becomes unsuitable, since all of that sub-order are 

 apterurous. It contains two legions, the Drorninea and 

 Ranininea. 



Legion 1 . Drominea. 



The carapace is subglobose or subquadrate, the 

 ' front ' narrow. The third maxillipeds have the third 

 and fourth joints subquadrangular. The lateral apode- 

 rnata 1 of the trunk are united in a common centre, form- 

 ing a sternal canal. The last pair, and often the last two 



1 The apodemata or apodemes are processes formed by an infolding 

 of the cuticle and extending inwards to give surfaces of attachment for 

 the muscles and to assist in protecting the internal organs 



