Palaeozoic Arachnida of North America. 51 



The arrangement of the coxae is different from that of the pre- 

 ceeding species. The first coxae alone show maxillary lobes which 

 are long, slightly curved and somewhat pointed at the distal end. 

 If the second coxae had any maxillary lobes there is no trace left 

 of them. The coxae themselves lie in front of the sternum. The 

 third coxae abut against the triangular part of the sternum, the 

 fourth against its sides. The sternum is distinctl}^ pentagonal, 

 longer than wide, and comparatively small. The genital opercula 

 are circular. The basal joint of the comb consists of two semioval 

 plates. The sternites of the abdomen cannot be made out with 

 clearness. The whole body is smooth. 



Found in the Pennsylvanic (Lower Allegheny) of Mazon Creek, 

 Illinois. 



Family Cyclophthalmidae 

 Eoctouus n. gen. 



Hand short and wide with almost straight, short fingers. Fifth 

 post-abdominal segment considerably longer than the preceding, 

 2^2 times as long as high. Genotype E. miniatus n. sp. 



Owing to the poor preservating of the specimens this genus is 

 as badly characterized as the other three genera, all from Europe, 

 belonging to the same family. Eoctonus may be distinguished 

 from Palaeomachus and Archaeoctonus by the shape of the seventh 

 post-abdominal segment and the hand ; from Cyclophthalmus by the 

 same characters as well as the shape of the cephalothorax. None 

 of the four genera, is however, sufficiently characterized to warrant 

 a safe position in the system and they have only relative value. 



Eoctonus miniatus n. sp. 

 Plate III, figs. 14, 15 ; text fig. 15. 

 This species is represented by two specimens in the Peabody 

 Museum. I chose as the holotype the specimen numbered 131 

 and represented in Plate III, fig. 14. Although both halves of the 

 nodule containing this specimen are in existence, the dorsal surface 

 alone appears on both. It shows the complete body, both mandibles, 

 one pedipalp, part of the fingers of the other pedipalp, and the 

 trochanters and proximal parts of femora of four legs of the left 

 side. Total length 14.0 mm. Cephalothorax a little narrower in 

 front than behind, 1.7 mm. long and 1.5 mm. wide at posterior 

 edge. Abdomen 5.7 mm. long; post-abdomen, not including the 

 poison gland, 6.6 mm. The right pedipalp is 5.2 mm. long, its 



