CYTHERELLA. 



71 



Fig. 12 of Plate VII is from a specimen collected by Mr. David Robertson, E.G.S., 

 of Glasgow, from the Musselband-ironstone of the Swinehill Colliery/ near Stonehouse, 

 Lanarkshire. 



This species is named after Mr. James Bennie, Collector to the Geological Survey of 

 Scotland, who has greatly aided ourselves and others in research among the Microzoa of 

 the Carboniferous Rocks. 



3. Cytherella recta. Sp. nov. Plate VI, figs. 6 «, h ; 11 «, h. 



Carapace neatly oblong, with round ends, and straight, parallel ventral and dorsal 

 edges, which, however, are sometimes rather incurved ; profile more than half as thick as 

 the height of the valves, slightly compressed anteriorly, and only slightly swollen poste- 

 riorly. Muscle-spot occasionally visible. 



mm. mm. Proportions. ^ 



Length -84 -76 . 21 19 



Height -48 -36 . 12 9 



Thickness '28 "28 . 7 7 



Eig. 11, from the Hosie Limestone or Shale at the Head of Mousewater, near 

 Wilsontown,^ Lanarkshire (Geol. Survey Scotland), has an unusual swelhng at the 

 postero- ventral margin, but the force of this exceptional irregularity is overruled by the 

 typical compression. 



Fig. 6, also collected by the Geol. Survey of Scotland, is from the Upper Limestone 

 Series, at Auchenbeg,^ Lesmahago. It occurs also in shale of the Lower Limestone 

 Series at Thornton,* East-Kilbride district, Mr. D. Robertson's collection. 



Reuss's C. paraUela, in Haidinger's ' Abhandl.,' iv, pi. 6, fig. 1, is much like our 

 C. recta, but is sharper in the profile anteriorly, and relatively fuller behind. 



4. Cytherella concinna. Sp. nov. Plate VI, fig. 9 and figs. 12 a, b ; figs. 19 a, /5? 



Carapace subovate, or rather long-ovate ; smooth ; profile bluntly lanceolate, narrowed 

 in front, truncated behind. These two specimens, though not quite coinciding in outline, 

 will scarcely bear parting. Fig. 12 is narrow-obovate, inasmuch as its front end is 

 rather broader than the other. Fig. 19 possibly belongs to this species. 



Length 1*16; height '6; thickness '44 mm. Proportions 29 : 15 : 11. 



1 'Catal. W.-Scot. Fossils,' 1876, p. 90. 



2 Lower Limestone Series, ' CataL W.-Scot. Fossils,' 1876, p. 92. 



'Catal. W.-Scot. Fossils,' 1876, p. 86. We have before now referred to C. recta from Auchenbeg as 

 " C. paruUela, J. and K.," see the 'Explan. Sheet 31, Geol. Surv. Scot!.,' 1879, p. 83. 

 * 'Catal. W.-Scot. Fossils,' 1876, p. 81. 



