106 Alexander Petrunkevitch, 



Key to the Species of Trigonotarbus. 



1. Coxae of pedipalpi contiguous in median line almo ,t their entire 

 length. Coxae of first pair of legs touching each other 



T. schucherti n. sp. 

 + Coxae of pedipalpi not contiguous their entire length, coxae of 

 first pair of legs separated by the sternum 2 



2. The segment surrounding he anal operculum wider than long. 

 Abdominal sternites moderately recurved 



T. carhonariiis n. sp. 

 + Segment surrounding the anal operculum much longer than 

 wide. Three adjoining abdominal sternites strongly recurved 



T. johnsoni. 



Trigonotarbus schucherti n. sp. 

 Plate X, figs. 53, 54; text figs. 63, 64. 



The type and only specimen of this species is in the collection of 

 Peabody Museum under No. 169. The reverse shows an almost 

 complete specimen. The obverse shows besides the dorsal sur- 

 face the superimposed impression of the reverse. This is especi- 

 ally clear if one examines the position of the anal operculum. 

 On the ventral surface it is median in position, whereas on the 

 obverse it is lateral, showing that the two surfaces were laterally 

 dislocated. 



Total length 19.0 mm. Cephalothorax triangular, with slightly 

 recurved posterior edge and curved sides, produced anteriorly into a 

 blunt lobe ; length in median Hne 7.5 mm., width at posterior edge 

 7.0 mm. ; high, gradually sloping in all directions. Abdomen oval. 

 Pleural sclerites not subdivided. Visible on the dorsal surface are 

 eight tergites. Anal operculum ventral in position. The plate sur- 

 rounding it is considerably Wider than long, representing probably 

 the fused sternite and tergite of the tenth segment In front of it are 

 seven sternites with moderately recurved edges. In two places the 

 sternites were evidently separated from each other by the pressure 

 of the drying mud in which the specimen was imbedded, exposing the 

 anterior margin of the sternites of the fourth and sixth segments 

 (second and fourth visible sternites). Sternum long and narrow, 

 reaching to base of first coxae, with lateral projections between each 

 consecutive pair of coxae and a narrow process separating the fourth 

 coxae. Coxae of pedipalpi triangular, contiguous their entire length 

 with exception of a small distal space. Chelicera missing. Pedipalpi 



