500 Dr. L. Moysey — Coal-measure Arthropods. 



also from before backwards. Its postero-lateral border is deeply 

 emarginate, and its posterior border is prolonged backwards in the 

 median line. The penultimate segment is fairly perfect, about three 

 times as broad as long. 



The ante-penultimate segment overrides the penultimate owing to 

 the crushing of the fossil, and is very imperfect, its anterior border 

 being chipped off. It appears, however, to have been similar to the 

 penultimate segment. 



The succeeding segment is very crushed, and overrides the last 

 described, and is so intimately confused with the fragments of 

 succeeding segments that it is impossible to make much out of it. 



On the ultimate segment, in the median line, and half-way between 

 the anterior and posterior border, occurs a minute circular pore, which 

 may doubtfully be referred to the anal orifice, but is so minute that it 

 could well be the opening of an odoriferous gland, similar to those 

 found on the side of the body of modern Myriapods. The chief point 

 of interest, however, in this specimen, is a double row of transversely 

 placed, crescentic openings, somewhat raised from the general surface, 

 and with tumid margins, which occur on each segment. One row is 

 placed far out towards the lateral margin and the other on each side 

 the median line. These openings are so similar in appearance to the 

 respiratory stigmata found in scorpions and other Arachnids, that we 

 may safely conclude that they had a similar function. 



If correctly interpreted, the presence of stigmata and the doubtful 

 anal orifice make it certain that we are here dealing with the posterior 

 ventral plates of an air-breathing Arthropod, although their curvature 

 and appearance of overlapping give the impression that they are the 

 dorsal plates. The presence, however, of two pairs of stigmata on 

 each segment is peculiar, and it is difficult to correlate this specimen 

 with any living or fossil form. 



FlG. 4. Post-abdominal segment of Scorpion. Coal-measures : Shipley, 

 near Ilkeston, Derbyshire. One and a half nat. size. 



Pig. 4, Segment of body of a Scorpion. This is probably one of 

 the post-abdominal segments of one of the scorpions, and is of 

 interest mainly because the remains of scorpions are extremely rare. 

 Two other examples, more pei'fect than this, have been obtained 

 from this coal-field, one described by Dr. II. Woodward, 1 from 

 the neighbourhood of Chesterfield, and another found by myself 

 from the Digby Clay-pit, Kimberley, Nottinghamshire, and described 

 as JSobuthus holti by Mr. P. I. Pocock. 2 The present example 

 occurs in a rounded ironstone nodule. Its anterior part consists 



1 H. Woodward, Geol. Mag., 1875, p. 622. 



2 E. I. Pocock, loc. cit. supra. 



