118 



Alexander Petrunkevitch, 



Geratarbus lacoei Scudder. 

 Plate XI, fig. 68; text figs. 71, 72. 

 G. lacoei Scudder, Mem. Boston Soc. Nat. Hist., Vol. IV, 1890, 

 p. 448, pi. 40, fig. II. 



The type and only specimen of this species. No. 1765 of the Lacoe 

 collection, is in the U. S. National Museum under No. 37966. The 

 obverse shows the dorsal surface with the impressions of the coxae 

 superimposed over the cephalothorax, the reverse shows the ventral 

 surface clear ; but abdominal sternites are totally obliterated on both 



Fig. 71. Fig. 72. 



Figure 'ji.— Geratarbus lacoei Scud., holotype, U. S. N. M. No. 37966, dor- 

 sal surface. Figure 72. — Same, ventral surface. X -p 



the obverse and reverse. The description given by Scudder is in- 

 correct in many points, he having omitted to clean the kaolin off 

 the specimen. 



Total length 10.5 mm. Cephalothorax 3.6 mm. long, 4.2 mm. wide. 

 Its posterior edge very slightly procurved, almost straight. The sides 

 are parallel, the anterior corners rounded. The anterior edge pre- 

 sents a broad projection in the middle with sloping sides and trun- 

 cated front. Immediately behind this projection is a more or less 

 triangular depression with rounded angles and emarginate sides, re- 

 presenting probably the eye tubercle. Abdomen oval. The anal 

 operculum appears on both the ventral and dorsal surfaces, but must 

 have been ventral in position. Of the ten tergites, the anterior five 

 are short, with heavily thickened posterior edge, typical of the order. 

 The pleura is not segmented and was evidently soft. Chelicera 



