Palaeozoic Arachnida of North America. 



65 



palpi are heav\- and rather short and the immovable finger is formed 

 by the tibia and not by the patella. The coxae of the first pair of 

 legs are unusually heavy, the femur 7.3 mm. long, getting evenly 

 thinner toward its distal end. The patella is about as long as the 

 coxa. Whether the last visible joint represents only the tibia, or 

 whether some joints of the tactile organ form the end of it, is not 

 possible to decide. The second, third and fourth pair of legs Were 

 short and stout and their coxae at even distances from each other. 

 The whole body is smooth. 



In the same nodule is a marine lamellibranchiate. 

 Specimen No. 147 of the Peabody Museum. Plate \ , fig. 25 ; 

 text figs. 25, 26. Paratype. 



Total size 22.0 mm. Cephalothorax 5.65 mm. long, 4.3 mm. wide 

 in the widest place, has the same shape and structure as in the type 



specimen. Middle eyes not 

 preserved. Mandibles \'isible 

 only on the obverse. Palpi 

 much heavier than in the 

 type specimen, their fingers 

 not preserved. The sternum 

 as in type, but the meta- 

 sternum clearly visible in 

 front of the first abdominal 

 sternite, separating the hind 



Fig. 25. 

 Figure z^.—Geralinura gigantea n. sp., paratj-pe, Peabody Mus. No. 147, 



ventral surface. Figure 26. — Same, dorsal surface, X 



coxae. The first abdominal sternite with a procurved posterior 

 edge. The second with both edges procurved, almost concentric. 

 At the posterior edge the impression of a semilunar genital opening. 

 The last three abdominal segments set off sharply from the preceding 

 segment, much as in recent whip scorpions. Of the legs only frag- 

 Tbans. Conn. Acad., Vol. XVIII. 5 June, 1913. 



