THE CIRRIPEDIA 107 



anatomical investigations of Cuvier. Lamarck, who was the first 

 to give them the name " Cirrhipedes " (later corrected by Burmeister 

 to Cirripedia), referred more or less vaguely to their affinities with 

 Crustacea, as did also Oken and others, without definitely removing 

 them from the Mollusca. 



It was not until J. Vaughan Thompson, in 1830, described the 

 development of Balanus from the " Cypris " larva that the Crustacean 

 nature of the group was placed beyond dispute. A little later 

 Burmeister (1834) and Thompson himself (1835) completed the out- 

 line of the life-history by discovering the earlier nauplius stage, 

 confirming the long -forgotten observations of Slabber, who had 

 figured the nauplius of Lepas as early as 1767. Although notable 

 contributions to the anatomy of the group were made by Martin 

 Saint- Ange (1835) and others, its taxonomy remained in the hands 

 of conchologists, and new genera and species were established on 

 the superficial characters of the shell alone. It is curious to note, 

 as a survival of this period, that so recently as 1906 it was thought 

 necessary to include a chapter on Cirripedes in a conchological 

 work. Darwin's Monograph of the Cirripedia (1851-54) placed 

 the study of the group upon a new basis, and indeed still remains 

 the chief work of reference on the subject. The discovery of the 

 " complemental males " and of the remarkable genera Cryptophialus 

 and Proteolepas (the latter not since re-observed) are due to Darwin, 

 while his systematic treatment of the normal Cirripedia (Thoracica) 

 has scarcely been modified by subsequent workers, except as regards 

 the addition of new species, for the most part from the deep sea. 

 Some anatomical errors in Darwin's work were soon after corrected 

 by Krohn (1859). J. V. Thompson had already in 1836 pointed 

 out the resemblance of the nauplius larva of Sacculina to that of the 

 Cirripedia, arid Lilljeborg (1859-60) established for that genus and 

 its allies the group of " Cirripedia Suctoria," and showed that they 

 passed through a "Cypris" stage. Fritz Miiller (1862-63) gave a 

 more detailed account of the anatomy and larval stages of this group, 

 to which he gave the name Rhizocephala. Delage, in a remarkable 

 memoir (1884), made known, for the first time, the complete life- 

 history of Sacculina, and his results, though received with scepticism 

 by some, have recently been confirmed by G. Smith (1906). The 

 group of Ascothoracica was established by Lacaze-Duthiers (1883) 

 for the very remarkable genus Laura, and other genera have been 

 added by Norman, Fowler (1889), Knipowitsch, and others. Among 

 the more important contributions to the study of the normal Cirri- 

 pedes may be mentioned the works of Hoek on the " Challenger " 

 collections (1883-84), Aurivillius (1892-95), and Gravel (1904), 

 and on the larval stages those of Glaus (1869), Groom (1895), and 

 Hansen (1899) 



