676 



ARTHROPODA 



SUB-KINGDOM VII 



is from the Permian of Bussaco, Portugal, where it occurs in association with land plants 

 ( Walchm, Sphenopteris}. Type, E. remipes, Dekay. 



Echinognathus, Walcott. Imperfectly known. Cephalo thoracic appendages with 

 numerous curved spines, indicating an animal of large size. Ordovician ; New York. 



Dolichopterus, Hall. Sixth 

 cephalothoracic leg has the two 

 moieties of the terminal joint sub- 

 equal in size, and developed as 

 two distinct joints, making nine 

 instead of eight elements in these 

 appendages. Otherwise as in 

 Eurypterus. Waterlime (Upper- 

 most Silurian) ; New York. 



Eusarcus, Grote and Pitt 

 (Drepanopterus, Laurie ; Eurysoma, 

 Carcinosoma, Claypole). Eury- 

 pterids with the first six abdominal 

 segments greatly expanded, those 

 following being abruptly con- 

 tracted. Terminal joint of the 

 sixth cephalothoracic appendage 

 not expanded. General aspect of 

 body scorpion - like. Silurian ; 

 New York, Indiana, Pentland 



FIG. 1420. 



Hills. 



Anthraconectes, 



M. and W. 



Eurypterus remipes, Dekay. Waterlime (Silurian) ; Buffalo, 

 New York. Ventral surface of young individual. The first (2nd ?) 



pair of legs, relatively large size and length of swimming feet, Like Eurypterus. but without spines 

 and abrupt posterior contraction of abdomen are especially . . . ., , 



notable. 3/ x . on the joints of the cephalothoracic 



appendages, and the median process 

 of operculum with two accessory lateral plates. Coal Measures ; Illinois. 



Adelophthalmus, Jordan and v. Meyer. Eyeless Eurypterids. Coal Measures ; 

 Saarbriicken. 



Eurypterella, Matthew. Very small, elongated forms. Cephalothorax small, 

 triangular ; the first four abdominal segments together sub-quadrate 

 in outline. Surface "tuberculated on the posterior edge of the 

 segments. Devonian ; New Brunswick. 



Slimonia, Page (Himantopterus, Salter), (Fig. 1422). Body 

 attaining a length of 60 cm., and width of 15 cm. Cephalothorax 

 sub-quadrate, with anterior marginal eyes and median ocelli. Preoral 

 appendages in the form of small stout pincers, much like chelicerae 

 in Limulus, but probably masticatory rather than prehensile. Of 

 the five pairs of postoral appendages, the first is modified to form 

 tactile organs, and is small and chelate ; the second also slender Buffalo, New Ymk. 

 and probably tactile. The first seven abdominal segments much Jj^i sh'owing^the 

 wider than the rest, and divisible into two parts, a dorsal (tergite) strongly anterior posi- 



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JJJJj 



1/1- 



and a ventral (sternite). The first two sternites are represented by 

 the genital plate and its posterior divisions ; the other five are 

 discontinuous plates bearing branchial lamellae on their inner 

 surface. The five posterior segments are long, narrow, and 

 cylindrical. Telson like that of Pterygotus, but produced into a longer spine. 

 one species. Old Red Sandstone ; Scotland. 



Stylonurus, Page. Body similar in general proportions to Pterygotus, and often 

 exceeding 1 m. in length. Cephalothorax quadrate or sub-pentagonal, its margins 



Only 



