TIIE MEROSTOMATA. 



233 



vided with toothed basal joints, are attached to the sternal 

 surface of the shield, and the mouth is covered, behind them, 

 by a large oval plate which appears to represent a meta- 

 stoma (Fig. 59, J3, g). Some of the anterior limbs are fre- 

 quently chelate {Ptenjgotus) ; the terminal joints of the most 



Fig. m.-Emnmterm remives (after Nieezkowski).^ , boreal aspect B ventral 

 aspect. Oth, the cermalo-thoracic shield bearing a. the eyes and 6, . c, d e t, the 

 locomotive limbs; T, tclson ; g, the metastoma; A, the sternal plates of the an- 

 terior free somites. 



posterior pair are generally expanded and paddle-like. The 

 integument often presents a peculiar sculpture, simulating 

 minute scales. The sternal surface of one or more of the 

 anterior free somites is occupied by a broad plate, with a 

 median lobe, and two laterally-expanded side-lobes (Fig. 59, 



1 " Der Eurypterus remipes, aus den obersilurischen Schichten der Insel 

 Oesel." 1859. 



