70 FOSSIL CIRRIPEDIA. 



f f . Scuta, ant longitudinaliter aut transverse {i. e. secundum tineas incrementi) costata. 

 16. POLLICIPES STRIATUS. Tab. IV, fig. 5. 



P. valvis longitudinaliter striatis : scutis sub-triangulis, margine tergo-laterali valde 

 arcuato et prominente ; costd obscurd, rotundatd, ah apice ad angulum baso-lateralem de- 

 currente ; interna apicis superficie solide repletd, sulcus manifestus deest. 



Valves longitudinally striated : scuta subtriangular, with the tergo-lateral margin much 



tergo-laterali segmento ex lineis incrementi rejlexis formato, angustissimo. Tergorum, costd recta, laid, pro- 

 clivi ab apice ad angulum basalem decurrente ; angulo basali scutum versus, oblique truncato. 



Scuta thick, approaching to an equilateral triangle ; occludent margin exteriorly strengthened by a 

 rounded ridge ; base-lateral angle widely truncated, equalling half the length of the true basal margin ; 

 tergo-lateral segment formed by the upturned lines of growth, extremely narrow. Terga with a straight, 

 broad, steep-sided ridge running from the apex to the basal angle, which latter on the scutal side is obliquely 



truncated. 



Faxoe ; Denmark. Mus. Univers., Copenhagen. 



Professor Steenstrup has kindly sent for ray examination a large series of scuta, terga, and cariuse, all 

 from the same formation of Faxoe, and no doubt belonging to the same species. 



All the valves are rather strong and thick ; they are smooth, with the exception of the fine lines of growth. 

 Scuta (fig. Af, nat. size, in a reversed position compared with the other figures,) triangular, with the baso- 

 lateral angle largely truncated ; considerably convex ; breadth, nearly equalling three fourths of length ; 

 apex acuminated, slightly curved towards the terga. Occludent margin nearly straight, forming an angle 

 considerably less than a right angle with the basal margin ; this latter is short and nearly straight ; the 

 tergo-lateral margin is just perceptibly concave ; a very narrow slip is formed along this margin by upturned 

 lines of growth ; this margin, if produced, would meet the basal margin produced, at a less angle than the 

 occludent margin does. The baso-lateral angle is so largely truncated that the side so formed is half the 

 length of the proper basal margin, which it meets at a very large angle ; it is doubtful whether it should be 

 called part of the basal, or of the tergo-lateral margin ; it touches, I suspect, exclusively the latera, but in 

 comparison with the other valves of this genus I do not think it corresponds with the ordinary tergo-lateral 

 margin. Externally there is a slightly depressed line running from the apex parallel and near to the occlu- 

 dent margin, causing this edge of the valve to appear convex and protuberant ; two slight ridges also run 

 from the apex — one to the angle uniting the basal and the above-described truncated margin, and the other 

 line, which is rather fainter, runs down the valve half way between the first line and the occludent margin. 

 Internally, there is a deep, upwardly pointed pit for the adductor muscle ; the internal occludent edge keeps 

 the same width up to the apex ; the internal tergal margin has no furrow, but is slightly indented, and must 

 have, to a certain extent, overlajiped the thin edge of the terga, and thus partly locked the valves together. 



Terga (fig. 4, d, e), rhomboidal, much elongated, almost flat ; occludent and upper carinal margins 

 (meeting each other at less than a right angle) much shorter than the lower carinal and scutal margins. 

 From the apex to the basal angle, down almost exactly the middle of the valve, a flat-topped ridge, either 

 absolutely straight or nearly so, runs, and widens considerably in its downward course ; its carinal side is 

 steep, its opposite side less so ; the oblique end of this ridge forms the basal angle, which is nearly, but not 

 exactly parallel to the upper carinal margin. There is no depression parallel to the occludent margin. 



Carina (fig. 4, a, b, c) much elongated, very slightly bowed inwards ; transversely, arched flatly ; barely 

 8ub-carinated ; basal margin almost rectangularly protuberant. Apparently, a full upper half of the carina 

 projected freely ; this part is filled up flat and solid (c) ; a rather wide inner margin of the carina extending 



