Cretaceous and Tertiary Cirripedes. 181 



Pycnolepas brilnnichi, nom. nov. 

 (Plate VII. tigs. 5-9 ; Plate VIII. fig. 6.) 



1839. Pdllicipes rit/i(h(s, J. de C. Sowevb}' ; J. Steeustrup, Krc^yer's 



Naturhist. Tidaskrift, J5d. ii. p. 404, pi. v. tigs. 24-20 (non P. rtyidua, 



J. de C. Soweibv, hSiU). 

 18ol. Pollicijx's vleyuns, C R. Darwin (non Lesson), Pal. Soc. Monogr. 



Foss. Lepadid;ie, p. 7(5, pi. iv. tig. 9. 

 1854. I'ollicipes elct/atus, C. U. Darwin, Hay Soc. Monogr. Subclass 



Uirripedia, Balanidie, Synop. et Index Systematiciis, p. (JoQ. 

 1857. Mifella eleynns, 0. li. Darwin, sp. ; J. Bosquet, Notice sur 



quelqiies Cirripedes dans le Terrain Cretace du Duc)i(5 de Limbo urg, 



p. 14, pi. iii. figs. 3«, b. 

 18ii5. Pvl/kipes eleyajis, C. R. Darwin ; J. W. Salter & H. Woodward, 



Cat. & Chart Foss. Crustacea, p. 27, pi. i. fig. 9. 

 1912. Pollicipes eleyans, C. R. Darwin; K, 13. Nielsen, Medd. Dansk 



geol, ¥oxtiii. J5d. iv. p. 32, pi. i. tigs. 18-20, pi. ii, figs. 1-8, 11, 12 



Cuontigs. 9, 10, 13-18). 



Diagnosis. Capitular valves transversely and longitudinally 

 ridged. Scuta subtriangular, Avith a broad wall-sided ridge, 

 soiuetiiues broader than the tergo-lateral portion, curving 

 from the apex to the basi-lateral angle. Terga with the 

 apical portion only slightly curved towards the scuta, and a 

 similar but narrower ridge extending almost straight from 

 the apex to the basal angle. 



Bistribntion. Danian : Faxe, Denmark ; Ignaberga, Scania. 

 Matstrichtiau : Bemelen, Duchy of Limbourg, Holland, and 

 Ciply, Belgium. 



Type. Steenstrup originally described a scutum, tergum, 

 and carina of this species as Pollicipes rigidus, J. de C. 

 Sowerby. Darwin subsequently described the species as 

 new, but inadvertently gave it the name Pollicipes elegans, 

 already, as he well knew, used bv Lesson (1830, " Voyage de 

 la ' Coquille,''' vol. ii. p. 441; 1831, Illust. Zool. pi. xxxix.) 

 for a recent species. 



Darwin's material consisted of three scuta, a tergum, and 

 two carinie received from Prof. Steenstrup, and of two scuta 

 collected by N. P. Angelin. Since Cirripedes have already 

 been named after both Darwiu and Steenstrup, I name this 

 after Dr. K. Biiinnich Nielsen, to whom we are indebted for 

 our present knowledge of the species. 



Dr. J. P. J. Bavu has most kindly searched among the 

 Steenstrup collection in Copenhagen University, and informs 

 me that he can identify neither the valves figured by Steen- 

 strup as P. rigidus nor those figured by Darwiu as P. elegans. 

 Prof. G. Holm also writes to say that the two scuta mentioned 

 by Dai win as collected by N. P. Angelin are not in the 

 Riksmuseum, Stockholm. They were probably in the 

 Steenstrup collection. 



