4 



BRITISH FOSSILS. 



of the head for comparison, we are compelled to regard it as a dis- 

 tinct species. It may be called — 



iEGLINA MAJOR. Fig. 9. 



Diagnosis. uncialis et ultra^ Icevigata ; thorace regulariter convexo, 

 sulcis axalihus hand profundis ; axi lato, antice ter, postea bis pleuras 

 superante ; pleuris truncatis ohtmis^ paullum deflexis, fulcro ad tertiam 

 posifo ; Cauda magna, semicirculari, regulariter convexd nec marginatd; 

 axi late conico, ad apicem obscuro, annulis binis ; lateribus trisulcosis, sulco 

 antico profunda, reliquis obscuris. 



This specimen has lost the head and first thorax ring.* The re- 

 maining portion measures three quarters of an inch in length, by 

 seven lines in breadth, and of this the tail is four and a half lines 

 long, and equal to the thorax. The general convexity is consider- 

 able, and equal over all parts ; the axis is separated from the pleurae 

 by a sharp but not deep sulcus, and is broader in front than behind, 

 in the proportion of four to three. The anterior ring being broken 

 off, however, we can only compare the axal portion with the second 

 pleura, and it appears to be rather less than three times its width. 

 The last pleura is half as wide as the axis of that segment. 

 The pleurae are blunt at their ends, facetted anteriorly, and have 

 the fulcrum placed at one third from the axis, from which point 

 they bend a little backward and downwards with the general 

 convexity. The pleural groove is less deep than in the former 

 specimen, probably because this one has not suffered longitudinal 

 pressure. 



The tail is a semicircle, equally and regularly convex, with no 

 raised border. The axis is but very slightly marked, it is broad 

 above, then rapidly narrowing, and soon lost before reaching one 

 third down the tail. One distinct ring is marked off on its upper 

 portion. The sides have the usual facetted external angle, and the 

 equally constant strong upper furrow (which might be called the 

 articulating furrow, being always present in some form or other) ; 

 below this there is a second much fainter one, at the distance of a 

 thorax segment's breadth, parallel to the upper fmTOw ; and a third 

 closely approximating to the second at its origin, aud then diverging 

 downwards. These furrows, except the uppermost one, are faint. 

 The tail is marked in some parts with a tranverse lineation, other- 

 wise it is smooth. 



* Unless this may be a 5-ringed species, -whicli is quite possible. 



