188 Mr. T. IT. Witlicrs on some 



known fossil Cirripedcs, and its A-alves are most beautifully 

 oruameuted. Tlicy measure respectively : — 



Leng-th. Breadth, 



mm. mm. 



Rostrum (holotype) 1"9 1"3 



Rostrum ' ll O'S 



Scutum 2-0 1-3 



Upper latus 2*4 1"2 



Description of Valves. Scutum (PL VIII. fig. 10) triangiilar, 

 slightly convex ; apical portion inclined from the opposing 

 scutum, acute, and curved towards the terga. Basal margin 

 almost straight; occludent margin convex; tergal margin 

 concave. Outer surface ornamented with fine transverse 

 ridges which are not upturned on the tergo-lateral half of 

 the valve. Where the transverse ridges are crossed by the 

 longitudinal ridges, they are produced into short sharp spines, 

 "which project outwards but not across the transverse ridges. 

 On the inner surface is a shallow pit for the adductor 

 muscle. 



Rostrum (PI. VIII. fig. 7) semiconical, slightly bowed in- 

 wards, basal margin semicircular, somewhat concave. Inner 

 surface thickened near the inner margins, and marked by 

 growth-lines which are continued under the apex to nearly 

 half the extent of the valve. Outer surface ornamented with 

 transverse ridges. On the larger specimen these ridges are 

 crossed by about seven longitudinal ridges, and are there 

 produced into short spines, similar to, but more pronounced 

 than, those on the scutum. Two of the longitudinal ridges, 

 which occupy a submedian position, are much thicker than 

 the others. Ou the smaller example the longitudinal ridges 

 are not so apparent. 



Upper lotus (PI. VIII. fig. 9) a very acute-angled isosceles 

 triangle, slightly bowed inwards. The outer surface is 

 ornaiiiented with prominent transverse ridges which bear 

 short spines arranged in longitudinal rows, and these spines 

 are evidently produced by longitudinal ridges crossing the 

 transverse ridges as in the other valves. Except for two 

 strong ridges in a median position, the longitudinal ridges 

 are not apparent between the transverse ridges. On the 

 inner surface the growth-lines meet on a raised, sharp-edged, 

 median ridge, which extends from about the middle of the 

 valve to the apex. The valve therefore overlapped the scuta 

 and terga to about half of its extent. 



Structure and Jffi/iities. This species is referred to the 

 genus Pi/cnolepas with some doubt, for, although the rostrum 



