264 REVISION OF THE MONAXONID SPONGES, i., 



" manuscript " names, and for the published equivalents of tliese 

 dependence has mainly to be placed on a synonymic list (herein- 

 after referred to as the key-list) furnished by the author of the 

 Catalogue at the request of the Museum Trustees some years 

 after his departure from Australia : the specimens also have 

 attached to them labels added by Mr. Whitelegge, indicating 

 their correct names according to the key-list, and marking them 

 to be the type-specimens. 



The examination of portion of this material, undertaken in 

 connection with my previous paper, disclosed that many of the 

 specimens were altogether incompatible with the descriptions of 

 the species they purported to represent; and that, as a rule, con- 

 siderable disagreement existed between description and specimen 

 even in those cases in which the latter had to be adjudged as 

 bevond question correctly labelled. So far as the evidence then 

 forthcoming enabled one to determine, however, the discrepancies 

 observed were, with two exceptions, such as it seemed necessary 

 to attribute either to inaccuracy of observation on Dr. Lenden- 

 feld's part or to a mislabelling of the specimens; the exceptions 

 — both of which T referred to in my previous paper — were in 

 connection, firstly, with Clathrissa arbnscula — the figure given 

 in illustration of whicl) is in reality one of Clathriodendron arhus- 

 cula\ and, secondly, with the two so-called varieties of Thalasso- 

 dendron riihens, the descriptions of whose skeletal characters 

 should be interchanged. The investigation of the remaining 

 material, while proving the descriptions to be almost without 

 exception faulty (often even to an extreme degree), has resulted 

 in the discovery that errors of the kind last-mentioned are by no 

 means of isolated occurrence in the Catalogue; in other words, 

 that not a few of the figures are wrongly designated, and that 

 in repeated instances the disparity between specimen and de- 

 scription is in consequence of the fact that the description is an 

 account partly of the external features of one species and partly 

 of the internal features of another. The former of these extra- 

 ordinary errors were comparatively easy of detection, and are in- 

 dubitable, since the actual specimens from which the figures were 

 taken have been found: but those affecting the descriptions only 



