36 THE NATURAL HISTORY REYIEW. 



"bers, presents all the essential marks of homogeneity. The chief 

 character by which the Cirripedia are distinguished from the Ento- 

 mostraca consists in their hermaphroditism, and Dr. Gerstaecker seems 

 to entertain some doubt as to the accuracy of Mr. Darwin's observa- 

 tions of the occurrence of " complemental males " in some species. 

 He adopts the opinion of Lilljeborg as to the Cirripedian nature of 

 the curious parasitic Sacculina and its allies, and admits them into 

 the system as forming a family, to which he gives the name of Suc- 

 toria, proposed for them by that author. 



The Crustacea conclude Dr. Gerstaecker's portion of this Manual 

 of Zoology, which, notwithstanding some minor defects, such as 

 those which we have briefly indicated, has evidently been executed 

 with great care and with a most conscientious desire to do full justice 

 to his subject. It is of course easy to cavil at some portions of his 

 system, but we must at the same time admit that he has produced a 

 most successful general view of the vast series of Arthropod animals, 

 while the generic types described as examples of the families are 

 generally judiciously selected, and the chief facts- in the life-history 

 of the animals, especially those bearing upon systematic Zoology, are 

 clearly, although of course very briefly depicted. 



Dr. Cams' section of the work, occupying just one-third of the 

 volume, strikes us as being rather slighter in its general execution ; 

 but when we consider the vast extent of systematic ground that he 

 has had to rim over in so short a space, and that the great extension 

 of the Arthropod section has evidently necessitated a correspondingly 

 increased compression of that devoted to the lower Invertebrata, we 

 may excuse some little shortcomings. 



Dr. Cams commences his work with the Eotatoria, which he 

 regards as a class forming a sort of appendix to the Arthropoda, and 

 under any circumstances they must be looked upon as constituting a 

 sort of transition between those animals and the true Vermes. The 

 author divides the Eotatoria into eight families, out of which he 

 claims five as newly defined by himself, although three of them were 

 certainly recognised and named long since, and admitted with very- 

 little diflerence of contents in Yan der Hoeven's " Handbook." 



The Vermes, although treated here as a primary section of the 

 Animal Kingdom, are not regarded by Dr. Cams as constituting a 

 distinct type, but only " as forms of that great series (Aunulosa) 

 which attains its climax in the Arthropoda." In this respect he 

 differs from Vogt, who even allows the Mollusca to intervene between 



