676 ARTHROPODA SUB-KINGDOM VII 
is from the Permian of Bussaco, Portugal, where it occurs in association with land plants 
(Walchia, Sphenopteris). Type, £. remipes, Dekay. 
Echinognathus, Walcott. Imperfectly known. Cephalothoracic 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 

Fic. 1420. Hills 
Eurypterus remipes, Dekay. Waterlime (Silurian); Buffalo, ; , 2 
New York. Ventral surface of young individual. The first (2nd 7) Anthracone tes, M. and W. 
pair of legs, relatively large size and length of swimming feet, Like Eurypterus, but without spines 
and abrupt posterior contraction of abdoufen are especially es 5 
notable. 3). on the joints of the cephalothoracie 
appendages, and the median process 
of operculum with two accessory lateral plates. Coal Measures ; Illinois. 
Adelophthalmus, Jordan and vy. 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 a(@ °) 
segments. Devonian; New Brunswick. DB 
Slimonia, Page (Himantopterus, Salter), (Fig. 1422). Body 6 
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 Pic. 1421, 
the five pairs of postoral appendages, the first is modified to form Bechet gd ree 
tactile organs, and is small and chelate; the second also slender Buttalo, New York: 
and probably tactile. The first seven abdominal segments much Ae ec 
wider than the rest, and divisible into two parts, a dorsal (fergite) strongly anterior posi- 
hs ee MySay i Cae tion of eyes, paucity 
and a ventral (sternite). The first two sternites are represented by of abdominal seg- 
the genital plate and its posterior divisions; the other five are ments, and pr 
discontinuous plates bearing branchial lamellae on their inner 1). ; 
surface. The five posterior segments are long, narrow, and 
cylindrical. Telson like that of Pterygotus, but produced into a longer spine. Only 
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 
