62 BRITISH PALEOZOIC PHYLLOCARIDA. 



genus. Except that the central spine (style) is the longest of the three, and the 

 stylets have smooth edges, this little fossil might be matched with C. E. Beecher's 

 Elymocaris siliqua, p. 13, pi. 2, fig. 1, of the ' Report Geol. Surv. Penns.' 1884. 

 The segment (about 8 mm.) was described by Mr. D. Sharpe as " simple and 

 rounded ;" the spines as " lancet-shaped," ..." the middle one somewhat 

 rounded and twice as long as the lateral plates, which are nearly flat." 

 " From the upper division of the Lower Silurian formation at Sazes, in the Serra 

 de Bussaco, near Coimbra." Collected by Senhor Carlos Ribeiro. In the Geological 

 Society's Museum, Cabinet 11, Drawer P. 



This set of spines is much stouter than the specimens Mus. Pract. Geol. d f-f , 

 PI. XI, fig. 10, and both stouter and shorter than the somewhat similar small set 

 in the Owens College Museum (PI. X, fig. 11). 



The telson is relatively short (about 10 mm.), smooth, ridged along the 

 middle, having a triangular section, and rimmed at the edges. The stylets 

 (about 6 mm. long) are strong, smooth, and rather thickened towards their outer 

 edges. 



This foreign (Portuguese) form, being within our reach, has been studied in 

 the Geological Society's Museum, Burlington House, and shows some interesting 

 features. Its scientific name was given by the late Mr. D. Sharpe under the 

 supposition that the fossil was a Dithyrocaris with a longer abdomen than usual ; 

 but its smooth and long ultimate segment, and its smooth style, seem to remove 

 it from that genus, as intimated in our ' Third Report,' p. 354. It is probably 

 distinct also from Ceratiocaris ; it has some analogy with the Devonian Elymo- 

 caris ; but at present we cannot fix its generic place. 



The caudal extremity of Ceratiocaris aculeata, J. Hall ('Geol. Surv. New 

 York,' vol. hi, part i, 1859, p. 422*, and part ii, 1861, pi. 80a, fig. 10), 

 from the " Waterlime Group," offers some alliance with this Portuguese form, 

 though of much larger size ; for its style appears to be short and strong, with a 

 median ridge. 



This interesting little Portuguese fossil is contained in a small nodule (27 X 23 

 mm.), broken open, dark grey within and ochreous outside ; not calcareous ; 

 containing several scattered minute Primitia (?). Around the central fossil the 

 matrix is blacker and rougher in section (limonitic). 



On the face of each half is the hollow cast of a nearly cylindrical, but slightly 

 tapering, tubular ultimate segment, 7 mm. long, by 5 mm. at the top, and 3 mm. at 

 its end, succeeded by a style or telson, 10 mm. long in the specimen, but not quite 

 perfect. Ochreous casts and impressions of the upper and lower parts of the 

 style are preserved in the nodule ; and they show that the style had a definitely 

 triangular section, with a ridge on its outer face, and slightly raised rims along 

 the edges. 



