Dr. H. Woodward — On Eurypterus Scoukri, Hibbert. 197 



Fig. 3. Eurypterus Scouleri, Hibbert, 1836. 

 ( Under side restored.) 



Fig. 2. Antennae. 3. Mandibles. 4. 1st Maxillae. 5. 2nd Maxillas. 

 6. Maxillipeds ; serving in tbis order as tbe cbief locomotory organs, m. Tbe 

 metastoma or post-oral plate. 7. Tbe tboracic plate or operculum, covering tbe 

 brancbise. Figs, i.-vii. Tbe bead-sbield. 1 Figs. viii. and ix. are concealed by 

 tbe operculum. Figs, x.-xix. Thoracico-abdominal somites destitute of any 

 appendages. Fig. xx. Tbe telson; or tail-spine. For dorsal view, see PL V. 



1 As the antennules in the Eurypterida are, theoretically, considered to he ahorted, the head- 

 shield would he really composed of the 7 cephalic and the 1st thoracic somites; but the Roman 

 numerals only indicate the number of somites coalesced in the head-shield which are actually 

 represented by paired appendages, reckoning the optic segment as the first, and the thoracic 

 plate or operculum as the seventh. 



