THE MERCSTOMATA. 



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, B, g). Some of the anterior limbs are fre- 

 quently chelate (Pterygotus) ; the terminal joints of the most 



Ct/L. 



Fig. 59.—Enriwterus remipes (after Nieszkowski). 1 — A. dorsal aspect. B, ventral 

 aspect. Cth, the cephalo-thoracic shield bearing a, the eyes, and b, c, d, e,f, the 

 locomotive limhs ; T 7 , telson ; g, the metastoma; h, 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. 



