AiiMralian Hydro ids. 115 



iince. >[any specific iiaiiies forinerly adopted by nic have liecii 

 ranked as synonyms of older species, following: on tlif (.'xamination 

 of n^useuni types of former observers. \Yhose descrijjtions -were so 

 incorrect or inaderi'iate that it had been impossible to identify the 

 species Avhich they were intended to indicate. This is especially the 

 case witli the hydroids descrilied by Lamarck and Lamouroux. of 

 whose descriptions a great many were quite valueless, so that the 

 species remained unidentified for nearly a century, till Dr. Billard 

 recorded the results of his examination of tlie type specimens. Tlie 

 same observer has also examined the British Museum collections, 

 and finds a numljer of the species (Australian and otlier) described 

 by Allman in tlie " C'liallen^er " Report, and elsewhere, to be 

 identical with previouxly-luiown forms (in addition to those Avhich 

 I had, in former papers, noted as synonyms of some of Busk's and 

 Kirchenpauer's species). I may i-emark in passing tliat a similar 

 revision of Kirchenpauer's types would be very serviceable. His 

 accounts of some of the species leave much to be desired, and in two 

 ■or three cases wliere the tyj^es have been examintMl. tlicy jn'ove to he 

 such as could not be I'ecognised from the descriptions and figures. 



A few of tlie speeies dealt witli in the following pages have been 

 treated by recent oljservei'S as synonyms of older sjiecies, from which 

 they are really distinct, and to clear up their affinities I have 

 <lescribed them more fully, though in fact, some of the original 

 descriptions were inconsistent with the synonymy assigned to them. 

 Two of Busk's species, which have only been identified in recent 

 years, are here fully described, and one or two changes are made 

 in specific names, for various reasons. In view of the unfortunate 

 vehicle of piiblication chosen by the Geelong observers (the " Geelong 

 Naturalist " being issiied in sueli limited numbers that scarcely any 

 copies were available for |niieliase), I proposed re-describing sucli of 

 the new species, as I had. tliidugh tlie coui-tesy of Mr. Mulder, 

 obtained specimens of, but have had to postpone doing so to a 

 possible future opportunity. 



I cannot let pass this occasion (the first which has presented itself) 

 •of expressing my hearty thanks to those observers who have favoured 

 me with their publications. These are : — Miss Laura Thornely. of 

 Liverpool; Dr. R. Kirkpatrick, of the British Museum; Mr. Jas. 

 Ritchie, of Edinburgh; Dr. E. T. Browne, of Beikhampstead ; Dr. 

 A. Billard, of Paris; Professor M. Bedot, of Geneva; Professor G. 

 M. R. Levinsen and Mr. P. Kramp, of Copenhagen; Dr. CI. Hart- 

 laub, of Heligoland; Dr. Elof Jaderholm, of Sweden; Dr. E. 

 :Stechow, of Munich; A. K. Link... of St. Petersburg: Dr. G. Mark- 



