118 BRITISH PALEOZOIC PHYLLOCARIDA. 



subcentral umbo, but there is no direct evidence of an open nuchal notch nor of 

 any cephalic or rostral piece to occupy it. The hinder part of the carapace had a 

 long triangular sulcus, either floored with a thinner kind of test, easily broken so 

 as to come apart in a line with the umbo, and leaving narrow lateral remnants, or 

 possibly sutured. Its ally Pholadocaris is not sutured. 



1. PiNNOCARis Lapworthi, B. Etheridge, jun. Plate XV, fig. 24. 



PiNNOCAEis Lapwoethi, B. Eth.,jun. Proc. Eoy. Phil. Soc. Edinb., vol. iv (1878), 



p. 169, pi. ii, figs. 3—5. 

 — — Nicholson and Etheridge, jun. Monogr. Silur. Foss. 



Girvan, vol. i (1880), p. 210, pi. xiv, figs. 17—20. 



PI. XV, fig. 24, resembles the Girvan specimen as figured (1880), especially 

 fig. 17, except that it has lost a part of the anterior rim, whilst fig. 17 has lost 

 part of the posterior rim. In that fig., and in fig. 20, the filmy ragged edge of 

 the posterior sulcus has been partly preserved, in fig. 17 its edge is entire, whilst 

 in fig. 18 such a ragged selvedge passes beyond the umbo to the front margin, 

 showing, apparently, that there was a continuous junction of the two moieties by 

 thin material throughout the carapace. PI. XV, fig. 24, is not altogether different 

 in this respect, though the posterior inner selvedge (on the right-hand side of the 

 figure) seems to have been thickened up into a wrinkled rim. It had a stronger 

 umbo than seen in figs. 17, 18, and 19 (Girvan), but this has been crushed down, 

 and is about the same as in fig. 20. There is no radiate ornament. 



In fig. 17 (Girvan) there is an associated sharp-pointed narrow body, which 

 has been regarded as being probably one of the tail-spines belonging to this 

 Phyllopod. 



These are from the Lower Silurian at Balcletchie, Girvan, Ayrshire. We 

 here figure, PI. XV, fig. 24, a specimen of the form or variety shown by fig. 17, 

 that is, with the hinder portion less pinched in, from the Upper Silurian of 

 Kendal. 



The shield is triangular-obovate ; if the two lateral pieces were complete and 

 laid out together the length would be about 25 mm. and the width 20 mm. It is 

 in the British Museum. I, 2952. 



No Goniatites accompany these specimens.^ 



' The Phyllopod described as accompanying Pinnocaris at Girvan belongs to J. M Clarke's 

 genus Dipterocaris (188.3 ; see our Report for 1884 (1885), p. 85). This is of Devonian age in the 

 State of New York, U.S.A. ; and, whether or not associated with Goniatites there, it is of Silurian 

 age and without Goniatites in this country. 



