386 Dr. H. Woochmrd — CyclosphcBroma in the Purhech Beds. 



abdomen coalesced together ; telson distinct, triangular in outline, 

 "with a strong median ridge, equal in length to the seven thoracic 

 segments ; surface of telson more sparsely ornamented, granulations 

 coarser, with three larger tubercles marking a small triangular area 

 at the proximal end of the median ridge. Traces of the epimera of 

 two coalesced abdominal segments are seen near the union with the 

 telson. 



x\lthough no appendages are preserved in the fossil, the deep 

 emargination on the sides of the telson, at its union with the 

 coalesced segments of the abdomen, indicates with certainty the 

 exact point of articulation of the last pair of pleopoda or uropoda, 

 as certainly as if they had been preserved in the fossil, and as 

 actually shown in place in the four recent examples figured on our 

 Plate XIV (Figs. 3, 4, 5, and 6). We give an ideal restoration of 

 these appendages below : — 



^ X 



Diagram of posterior segments and telson [z) of CychsplK^roma, with appendages 



restored. 



0, last thoracic segment (vii). P-z, abdominal segments and telson. v, paired 

 uropods or pleopods, appendages of last segment, ex, exopodite ; en, endopodite. 

 z, telson or terminal segment. 



Having consulted my carcinological friend, the Eev. T. E. E. 

 Stebbing, F.E.S., F.L.S., Tunbridge Wells, concerning the affinities 

 of this fossil, I am glad to know that, in the absence of appendages 

 to guide one more certainly, and from the general appearance of the 

 body itself, he considers that I am fully justified in referring it to 

 the Sphaeromidee. 



He has further suggested that the forms among recent members 

 of this family which appear to be most suitable for comparison 

 with it are the following : — 



1. Cassidina typa, H. Milne-Edwards.^ 



Hist. Nat. Crust., vol. iii, pp. 223-4, pi. xxxii, figs. 10-16. 



Milne-Edwards speaks of the side-plates as ending in an almost 

 straight edge, as in CyclosphcBroma. 



2. Cassidina emakginata, Guerin. (PI. XIV, Fig. 3.) 



This specimen is well represented in the British Museum by 

 specimens from Otter Island collected by Dr. Cunningham in 1868, 



1 I could not obtain a spirit specimen of C. ti/pa, so I decided to draw an 

 example of C. emarginata, Guerin, as preferable to reproducing a small and very 

 indistinctly-drawn figure of the former species. 



