Palaeozoic Arachnida of JVor/fi America. 83 



dorsal surface is uniformly punctuate. The underside of the abdomen 

 also uniformly punctate, has a procurved line, in front of which, in the 

 triangle between the hind coxae, are two parallel ridges and a deep, 

 hemispherical depression, probably the genital opening. All coxae 

 well preserved. Those of the first and second pair widely separate, 

 between them the sternum visible posteriorly as far as the posterior 

 end of the third coxae. Fourth coxae contiguous. Immediately be- 

 hind the ventral part of the cucullus is a large, almost round plate, 

 divided longitudinally in two by a median ridge. It is possible that 

 this plate represents the outer aspect of the chelicera. At the sides of this 

 plate are the coxae of the pedipalpi. Four joints of the left pedipalp 

 are visible, showing that the pedipalp was slender and that its tro- 

 chanter is two-jointed. Of the first pair of legs, which were con- 

 siderably thinner than the others and only little hea\aer than the 

 pedipalpi, are preserved both coxae and the trochanter, femur, 

 patella, tibia and metatarsus of the right leg. Of the second pair of 

 legs only the coxae and trochanters are preserved. Like that of the 

 first pair the trochanter is one-jointed, but extraordinarily large. 

 The legs of the third and fourth pair are almost complete, missing are 

 the metatarsi and tarsi. The femur of the first leg is short and stout 

 with a sharp apical process. The fourth femur is slender and long, 

 measuring 5.0 mm. The ventral surface is also uniformly punctuate 

 with the exception, however, of the parts minutely dotted on text 

 figure 48, which appear quite smooth. 



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

 Illinois. 



Curculioides sulcatus (Melander). 

 Plate VII, fig. ^8; text figs. 49, 50. 



= Kustarachne sulcata Melander, Jour. Geol., Vol. XI, 1903, p. 181, 

 pi. V, fig. 5, pl. VII, fig. 4. 



The type and only specimen of this species, No. 9235, is in the 

 collection of the Walker Museum of the University of Chicago. The 

 nodule containing it consists both of the obverse and reverse, but the 

 whole specimen was heavily covered with kaolin, this being the reason 

 why Melander's description is quite incorrect. Basing his opinion 

 on the similarity in the relative measurements of Curculioides sulcatus 

 and Kustarachne tenuipes, Pocock suggests in his Monograph that 

 "one shows the dorsal, and the other the ventral view of specimens 

 belonging to the same species." This suggestion is excusable only in 

 view of the fact that Pocock had no occasion to examine the specimens 

 themselves and based his judgment on the incomplete and erroneous 



