Dr. L. Moysey — Coal-measure Arthropods. 



503 



chelicera and first leg on the right side all emerge from under the 

 ■weathered anterior portion of the carapace. 



The body or opisthosomais well shown, consisting of eight segments. 

 The junction between the carapace and the first segment, the first and 

 the second, and the second and third, are straight and show well- 

 marked ridges ; the succeeding ones are not so well marked, and curve 

 with their concavity backwards more and more sharply until the 

 eighth segment is in the form of a horseshoe, enclosing on three sides 

 a more or less quadrilateral plate, at the anterior part of which is 

 placed a characteristically large anal ring in which can be detected the 

 anal orifice. 



FlG. 7. Anthracosirofritschii, Pocock. FlG. 8. Anthracosiro fritschii, Tocock. 



Showing carapace and opisthosoma, Dorsal view of opisthosoma. Shipley, 



with appendage. Ventral aspect. near Ilkeston, Derbyshire. Four 



Coal-measures: Shipley, near times nat. size. 

 Ilkeston, Derbyshire. Three times 

 nat. size. 



In this case we are dealing, as in the majority of specimens found 

 at Shipley, with the ventral aspect of the body. In two specimens 

 from this locality, however, we have preserved the dorsal aspect of the 

 animal (Fig. 8 supra). One of these gives the flat posterior area 

 of the carapace and a small portion of the left lateral region, also the 

 remains of two ambulatory appendages represented by their femora 

 on the right side. The opisthosoma consists of the usual eight 

 segments, the first being the shortest ; their posterior borders all run 

 sub-parallel to one another, the lateral laminae marked off from the 

 tergites by a definite line being directed more and more backwards, 

 until those of the eighth point directly backwards, and bound on either 

 side the quadrilateral backward extending plate of the eighth tergite. 



Fig. 9, Anthracosiro fritsehii, Pocock (dorsal aspect). The other 

 specimen is in an ironstone nodule mixed up with a confused 

 mass of neuropterid pinnules and other plant debris. The carapace 



