Fauna and Stratigraphy of tlie Storniberg Series. 329 



The smaller carapaces are isolated; the larger are attached in each 

 case to the body. 



The first antenna is short, single, possibly divided into two joints. 

 As seen in specimen 5752 and possibly in 5751 it is similar in 

 appearance to that of the recent L. viridis. The antenna is best 

 seen in specimen 5758. 



The second antenna cannot be distinguished. 



The mandible is apparently an elongate plate (breadth greater than 

 length) with a denticulate biting edge having 5 or 6 teeth. An 

 impression is seen in no. 5758. In no. 5752 the maxilla is seen 

 in juxtaposition with its neighbour of the other side. 



The segments under the carapace are all provided with setose 

 Phyllopod appendages. 



In one specimen there are about 17 segments protruding beyond 

 the carapace ; of these at least 7 are longer than the others and may 

 be regarded as true abdominal segments, although none of the seg- 

 ments are seen to possess feet. Each segment bears an encircling 

 row of sharp spines which diminish in number posteriorly. The 

 spines arise from near the middle of each segment and project well 

 back behind the posterior border. Excluding the telson the body is 

 about half the length of the carapace. (In another specimen the 

 body is shorter, and the number of abdominal segments apparently 

 six. This is possibly a female). 



The telson is moderately short, spatulate, with a fairly well 

 rounded posterior border and a pronounced longitudinal median keel. 

 It carries no spines, and the edge is entire. In specimen 5763, 

 however, the telson, instead of being spatulate, is somewhat pointed 

 at the end, like a spear-head, and the lateral edges seem to be 

 either serrate or provided with short spines. This may represent a 

 variety; but the specimen is otherwise too incomplete for lengthy 

 description. 



The caudal filaments are fairly broad at the base, taper fairly 

 rapidly and are covered with long fine hairs. 



Specimen no. 5752 shows an oval body 2'5 mm. long situated in 

 the neighbourhood of the 15th or 10th legs under the carapace, 

 behind the mid-line of the carapace and to the side. The body is 

 empty, but was probably an ovisac. 



The form has been placed in the genus Lepidurus on account of 

 the characteristic telson which distinguishes it at once from Apus. 

 As far as can be discovered Lepidurus has not hitherto been des- 

 cribed from Triassic deposits, although an allied form Apudites (or 

 Apus) antiquus has been named by Schimper from the Lower Trias 



