1106 



NEW YORK STATE MUSEUM 



The remnant of another appendage appears to be part of the 

 proximal four joints, and measures 32 mm in length. From its 

 robustness, it seems to have belonged just in front of the last 

 mentioned. The peculiarities of these joints are their shortness 

 and their thickening at the articulations. The joint, which on 

 the tablet lies nearest to the large arm, is a little inflated and, 

 though very imperfect, has the appearance of being the coxal 

 joint. 



The two other appendages of this group are robust and short. 

 One is tolerably complete, apparently lacking only the dentate 

 border of the coxal joint. It is 38 mm long and consists of seven 

 joints. The coxal is large and globose. Each joint from 

 the second to the fifth carries on the posterior edge a pair 

 of short, stout, distally directed, lanceolate spines, averaging 

 2.5 mm long and nearly half as wide. Joint two is broad 

 and very stout. Joints three, four and five are subquad- 

 rate and successively smaller. Joint six is nearly one and 

 one half times as long as broad and at the end bears two dis- 

 tally directed spines, one anterior, the other posterior. The 

 seventh is long and clawlike, slightly inflated at the base. The 

 other appendage is so crushed and folded that little can be 

 determined by it. However, from the larger size of the coxal 

 joint, it is probable that its position on the body was behind the 

 more complete. The spines preserved on it, like those of the 

 smaller appendage, are short and lanceolate. 



The body plate in this group is very narrow (76 mm) as com- 

 pared to its length (23 mm). Its division into right and left 

 halves by a suture, the arching of each half and the produced 

 anterolateral angles indicate it to have been a paired sternite. 



In the second group one of the imperfect arms consists of the 

 four distal joints, the other of two imperfect proximal joints. 

 The joints of the former are short and expanded at the articula- 

 tions. The first and second are each provided on the posterior 

 side with a pair of distally directed spines. These are long, 

 curved and sharp like those of the large arm of the other group. 

 The second has also, on the opposite side of the distal angle, a 

 single, large one extending parallel with the axis of the arm. 

 The penultimate is long and shows no sign of haying been 



