Crustacea — Merosfomata. 



77 



(II) Meeostomata. — Immediately following the Entomostraca are GALLERY 



the Merostomata, a very remarkable ffroup of Crustacea, some of 



. . . . . . Wall-cases 



which are of gigantic size. The mouth is furnished with mandibles ^3 g^ ^4 



Fig. \Si.—GriJit?iides Fig. 135. — Phillipsia Eichwaldi Fig. U6.—Fhillipsia De,'" 

 fflobiceps, Vortl. Car- var. mucronata, M'Coy. biensis, Martin. Car- 

 boniferous Lime- Carboniferous Limestone boniferous Limestone : 

 stone : Ireland. shale : Muirkirk. Derbyshire. 



"Wall-cases 

 13 & 14, 

 Table- 

 cases 

 80 & 82, 

 and Gal- 

 lery-walls 

 between 

 Wall-cases 

 12 & 13, 

 andl3&14. 



Fig. 137. — Pterygotus anglicus, Ag. (under-side). Old Red Sandstone : Forfar- 

 shire. 1, the compound sessile eyes; 2, the chelate antennae; 3, 4, 5, 

 the mandibles, maxillae, and maxillipedes ; 6, the great swimming jaw- 

 feet ; m, the metastoraa, or lower lip ; 7, the operculum, covering the 

 reproductive organs (8) and the gills (9) ; the other segments (10-19) are 

 destitute of any appendages ; 20, the telson, or terminal segment. 



