THE 



VOYAGE OF H.M.S. CHALLENGES. 



ZOOLOGY. 



REPORT on the Cirripedia collected by H.M.S. Challenger during the years 

 1873-76. By Dr. P. P. C. Hoek, Member of the Royal Academy of 

 Science of the Netherlands. 



INTRODUCTION. 



The Cirripedia form together a group of Crustacea which, generally (Gerstacker, Claus), 

 is considered as an Order. The information we possess with regard to this Order is by 

 no means insignificant : the splendid Monographs of which Charles Darwin has made it 

 the subject ! are alone sufficient to place it among the best known groups of inverte- 

 brate animals. The publication of these Monographs has been so eventful in the 

 development of our knowledge of the group that I may be allowed to divide the history 

 of that knowledge into two periods : — 



I. Before the publication of Darwin's Monographs ; and 

 II. From this publication up to the present date. 



It would be quite superfluous to enter into details with regard to the history during 

 the first period. As Darwin says in the preface of his Monograph on the Lepadidaj 

 (p. 8), this history has been fully given by Burmeister 2 and by Martin St.-Ange, 3 and 



1 Darwin, C, A Monograph on the sub-class Cirripedia, with figures of all the species, Lepadida; (1851), Balan 

 idae, Verrucidse, &c. (1854), London, Ray Society. A Monograph on the fossil Lepadida 3 , or pedunculated Cirripedea oi 

 Great Britain, London, 1851. A Monograph on the fossil Balanidse and Verrucidie of Great Britain, London, 1854. 



2 Burmeister, H., Beitrage zur Naturgeschichte der Rankenfusser, Berlin, 1S34. 



3 Martin Saint-Ange, G. J., Memoire sur l'organisation des Cirripedes et sur leurs rapports naturels avec les 

 animaux articules, Mem. Savans e'trangers, vi. p. 513-555, Paris, 18:)5. 



(ZOOL. CHALL. EXP. — PART XXV. — 1883.) Bb 1 



