898 THE AMERICAN NATURALIST. [VOL. XXXIII. 



been looked forward to with interest. After a considerable delay, 

 due to the late financial depression in Australia, the work has now 

 been published as Catalogue No. XVII of the Museum. That it is 

 of the highest order of scientific excellence hardly needs to be said, 

 particularly for those who are familiar with Professor Herdman's dis- 

 tinguished work in the past on this group of animals. 



The author has entitled his report a " Descriptive Catalogue of the 

 Tunicata in the Australian Museum, Sydney, New South Wales," 

 and he says that it is not to be regarded as a monograph on 

 Australian Tunicata. He tells us that he was expressly enjoined 

 by the trustees of the Museum " not to enter into anatomical and 

 histological details beyond what he considered necessary for the 

 elucidation of the systematic position and the sufficient description 

 of the various species." The fact, consequently, that he has devoted 

 nearly one hundred large octavo pages and forty-two plates to the 

 description of the sixty-two new species serves as an index to what 

 this veteran ascidiologist believes to be the briefest treatment con- 

 sistent with exactness in this group. 



In his introduction he gives a brief discussion of classification and 

 concludes that, despite the various quite radically different systems 

 that have since been proposed, he sees no sufficient reason for 

 departing widely from the one adopted by him in his Challenger 

 report of 1882. And he justly remarks that he feels himself 

 strengthened in his position by the fact that this system has been 

 quite generally adopted by recent writers, notably by Seeliger in his 

 " Tunicata " for Bronn's Klasscn und Ordnungen des Thierreichs. 



He does, however, introduce one modification of considerable 

 importance. He divides the Ascidiae composite into two sections, 

 one of which contains the "compact-bodied families," Botryllidae and 

 Polystyelidae, and the other the " remaining families with extended 

 or divided bodies." For these he proposes to adopt the names 

 " Holosomata " and " Merosomata," respectively, if Sluiter, who first 

 used them, but in a somewhat different sense from that in which 

 Herdman proposes to use them, will agree to Herdman's modifica- 

 tion. Or if Sluiter refuses to accept this modification, then Herdman 

 will adopt the terms " Pectosomata " and " Chalarosomata " for the 

 respective groups. 



There can be no doubt, particularly since the Polystyelidae and 

 Botryllidae have been shown to agree so closely in their method of 

 budding, that they should be associated more closely in classification 

 than either family can be with the other families of compound ascid- 



