44 Alexander Petrnnkevitcli, 



then turning more outward and rising again in shape of a low ridge 

 which joins the curved transverse ridge in the posterior end of the 

 cephalo thorax. The surface carr\'ing the alveolated area on each 

 side is more or less horizontal, but the surface inward from the lateral 

 curved ridges has a steep declivity toward the curved grooves which 

 begin on the sides of the ocular depression and meet in the median 

 line close to the transverse curved ridge. These grooves are out- 

 wardly accompanied by a row of small, round depressions. A heavy 

 ridge runs in the median line, gradually rising anteriorly and is highest 

 at the place where it forms a small fork. Immediately in front of 

 this fork lies the oval depression which represents evidently the mould 

 of the eye tubercle. It is very large, reaching anteriorly the edge of 

 the cephalothorax. Within the depression one may recognize a 

 triangular ridge and two pairs of oval depressions (one pair on each 

 side of the triangular ridge). These oval depressions look very much 

 like moulds of eyes. It is possible, however, that only the anterior 

 pair represents eyes, while the posterior pair is a mould of what may 

 have been chitinous granules. 



The number of abdominal tergites cannot be counted owing to 

 the presence of transverse lines Which represent probably artificial 

 folding of the skin. Moreover they are visible only on the left side 

 of the specimen, the right side being covered by wide plates which I 

 interpret as sternites. A proof of this interpretation I see in the 

 fact that the left side representing the tergites is concave, as in the 

 cephalothorax, while the plates on the right side are convex. All 

 abdominal plates are smooth. On the left side of the abdomen is 

 visible a part of a leg, four segments of which are complete. The 

 femur is 9 mm. long, the tibia 9 mm. and the metatarsus 6 rmn. 

 The legs on the right side of the specimen i-epresent a hopeless tangle. 

 One of them, however, is of extraordinary interest since it shows the 

 structure of the two last segments. We note one spine which was 

 probably in the articular membrane of the proximal tarsal joint. 

 The distal joint shows the impression of its ventral surface. One may 

 clearly distinguish a tubercle representing the walking spine, two long 

 claws, a median long, pointed dorsal lobe and two round depressions 

 behind the tubercle. Another fragment of a leg, lying in front of the 

 one just mentioned and probably representing a tibia, shows a row of 

 punctuated depressions along its inner edge. On the left side of the 

 cephalothorax is a long lens-shaped body, probably the transverse 

 section of a leg. Immediately behind the posterior left corner of 

 the cephalothorax is a bean-shaped depression, perhaps also a trans- 

 verse section of a leg. 



