Plate IX. 



Figure 1. — Geryon quinquedens Smith; dorsal view of the carapax of a large male (b) 

 from off Cape Ann ; four-fifths natural size. Figure la, frontal region of the same 

 specimen, seen from beneath; one and a third times natural size. Figure 16, ter- 

 minal portions of the chelipeds of the same specimen ; enlarged the same amount. 



Figure 2. — The same species ; dorsal view of the carapax of a small female (e) from 

 off Massachusetts Bay ; one and a third times natural size. 



Figure 3. — Geryon tridens Kroyer; dorsal view of the carapax of a large male from 

 Christiania Fiord, Norway; two-thirds natural size. Figure 3a, frontal region of 

 the same specimen, seen from beneatli : one and a third times natural size. 



Figure 4. — HipjMlyte pusiola Kroyer; tip of the telson of a female 20 •5'"°' long, from 

 the Bay of Fundy, with more than the normal number of terminal spines ; enlarged 

 thirty-two diameters. 



Figure 5. — The same species; tenninal portion of the telson of a female IG""" long, 

 from Halifax, Nova Scotia, with an abnormal arrangement of aculei and spines, 

 apparently resulting from some injury ; enlarged thirty-two diameters. 



Figure 6. — The same species; terminal portion of the telson of a male, 17""" long, 

 from the Bay of Fundy, with less than the normal number of terminal spines ; 

 enlarged thirty-two diameters. 



Figure 7. — The same species; terminal portion of the telson of a male, 15"™ long, 

 from near Cashe's Ledge, off the coast of Maine, with the normal arrangement of 

 spines ; enlarged thirty-two diameters. 



Figure 8. — Hippolyie Gaimardii Milne-Edwards; tip of telson of a female, 36""" 

 long, from Halifax, Nova Scotia, with the normal armament of spines ; enlarged 

 sixteen diameters. 



Figure 9. — The same species ; tip of the telson of a female, 39"^"! long, from Casco 

 Bay, with an abnormal armament of spines ; enlarged thirty-two diameters. 



