70 



A RE-EXAMINATION OF PROFESSOR HASWELL'S 

 TYPES OF AUSTRALIAN PYCNOGONIDA. 



By Professor T. Thomson Flynn, B.Sc, 

 Ralston Professor of Biology, University of Tasmania. 



Plates XVIII.-XXIL, figs. 1-26. 

 (Received 8tli July, 1919. Read 11th August, 1919.) 



Diagnostic methods in the case of the interesting group 

 of Pycnogonida have so far altered in the last thirty 

 years, that it needsi no apolog}^ on my part for attempting 

 a revision of the descriptions of Australian Pycnogonida 

 published by Professor Haswell in the early eighties. 

 This revision has been made possible by the courtesy of the 

 trustees and curator of the Australian Museum, who placed 

 the holotypes at my disposal, and to whom I tender my 

 best thanks. I have also tO' thank Professor S. J. Jolinston 

 of Sydney for the loan of other specimens collected for the 

 use of his department. 



In the following description the specimens from the 

 Australian Museiun are indicated by the collection 

 number. 



It is necessary to state that the holotypes have been 

 preserved as microscope slides, and while this is a con- 

 venient method of preservation it has its disadvantages 

 in the case of subsequent examinations. It is some- 

 times impossible, for example, to make put with any de- 

 gree of certainty the arrangement and structure of the 

 spines of the ovigeirs or even of its joints when, as is 

 often the case, it is tucked under the body of the Pycno- 

 gonid on a microscope slide. Further, while every care 

 has been taken with the measurements it must be remem- 

 bered that the flattening of the specimen necessary in 

 preparing a, mis:cro9copic slide, alters very definitely the 

 relation of breadth to length. 



Many of the works cited in the following pages are 

 not procurable; in Tasmaaiia, and in these cases I have to 

 depend on notes made when on a visit to Sydney. 



