1866.] WOODWABD DISCIJS^OCAIIIS. 503 



4. On a jSTew Genus of Phyllopodous Crustacea from the Moffat 

 Shales (Llandeilo Flags) Dumfriesshire. Bj Henry Woodward, 

 Esq., F.G.S., F.Z.S. 



[Plate XXY. figs. 4-7.] 



Having lately received from Mr. D. J. Brown, of Edinburgh, 

 specimens of shells, attributed to Discina and Modiolopsis, from 

 Garple Burn, near Moffat, I examined them in conjunction with my 

 colleague, Mr. "W. Carruthers, E.L.S. ; and we were enabled, by the 

 help of these specimens and of others in Mr. Carruthers's own collec- 

 tion, to determine them all to belong to one organism (folded in some 

 instances, and in others spread open), and that not a mollusk, but a 

 crustacean allied to Apus &c. 



The fossil might readily be mistaken for the upper valve of a 

 Discina, having a strong resemblance to Discina nitida from the 

 Carboniferous Limestone, and to Discina lamellosa, recent, from Peru ; 

 but upon a more careful examination nearly every specimen is 

 found to have in the front of the shell a wedge-shaped opening with 

 a well-defined border, which cuts the disk nearly to its centre *. 



In a specimen from Mr. Carruthers's collection (PL XXY. fig. 7) 

 the wedge-shaped sector which closes this opening remains in situ, 

 but the suture can still be detected. 



In another specimen, from Mr. Brown's collection (PI. XXY. 

 fig. 5), remains of the tail-segments are preserved on the same slab 

 with the folded shell. 



The carapace, for such it must be considered, is ornamented by 

 concentric lines of growth, which curve slightly inwards upon reach- 

 ing the margin of the wedge-shaped suture in front. These con- 

 centric lines are finer and closer to each other near the apex, and 

 more stronly marked and further apart near its margin. The sector 

 displays similar concentric lines of growth with the rest of the cara- 

 pace. The form of the shell is slightly conical, as in Discina ; but 

 many of the specimens, being crushed, do not show the normal form. 

 The apex of the shell is placed immediately behind the wedge-shaped 

 suture before mentioned. 



In all the specimens yet seen no dorsal furrow can be detected, 

 the concentric lines passing smoothly in unbroken series around 



* Mr. Davidson, to whom Mr. Brown had submitted certain other more 

 minute shell-like impressions from these shales, thus writes concerning them 

 and the fossil at present under consideration : — 



" 33 Park Crescent, Brighton, 

 " 27th October, 1865. 



" My dear Sir, — I send for your inspection the two specimens that were sent 

 to me by Mr, Brown, of Edinburgh, and which were derived from the Dum- 

 friesshire beds. They are certainly obscure fossils ; but the specimens yovi 

 showed me were not Brachiopoda, but, as you said, remains of Crustacea. 



" Those I send show no indications of the fissure, or notch, and have a much 

 more Brachiopodous look than those in London. One of them somewhat resem- 

 bles a Lingula, the other a Discina ; but I do not say they are Brachiopoda. 



" I remain, very truly yours, 



(Signed) "Thos. Davidson." 

 «' To H. Woodward, Esq." 

 _0L. XXII.— PART I. 2 M 



