268 DISCOVERY REPORTS 



developmental stages, young as well as adult, which were not present in the first 

 collection and required description. Moreover, the classification of the Hydromedusae 

 has been much altered since Mr Browne's original manuscript was written (alterations 

 partly introduced by Mr Browne himself in subsequent papers) ; and studies of the 

 very material at hand gave occasion for several taxonomic considerations which could 

 not easily be omitted, but for which I do not wish the late Mr Browne to take the 

 responsibility. I was much in doubt, therefore, as to the form of the publication, but I 

 am very glad to accept Dr Stanley Kemp's proposal and make it a joint paper under the 

 combined authorship of Mr Browne and myself. I feel the more confident in doing so, 

 because frequent communication and collaboration through many years has given me a 

 fairly intimate knowledge of Mr Browne's views and working methods, which to a great 

 extent he bestowed upon me through the influence he had on my own labour. I feel 

 convinced, therefore, that if we had discussed these matters together, as we used to do, 

 he would most probably have given his approval. 



Any attentive reader will easily be able to distinguish between my share in the paper 

 and Mr Browne's. The descriptions of the species are almost entirely Mr Browne's, 

 and I have found very little to alter in them apart from small additions of minor 

 importance. The same applies to the records of the development from the early stages 

 to the adults, except when developmental stages, not present in the first collection, are 

 found and described by me, which will always appear from the accounts of the material 

 following the "specific characters" of each species. I have also included some of 

 Mr Vallentin's interesting notes on specimens observed by him during his second stay 

 at the Falkland Islands. Remarks on the history and distribution of the species and 

 taxonomic discussions based upon literature subsequent to 1902 are written by me. 

 The alterations of nomenclature will appear from a comparison with Mr Browne's 

 preliminary report and from the lists of synonyms. The new species and genera 

 described in the preliminary report have all been maintained. 



The most important additions are the following : (i) Only one specimen of Staiirocladia 



vallentini was present in the first collection, and since the specimens collected in 1901 



differ slightly from the type, a somewhat detailed description of these specimens was 



necessary ; they also gave occasion for a thorough comparison with other species of the 



same genus, (ii) Tiara intermedia is referred to the genus Halitholus Hartlaub; 



Mr Browne once told me that he fully agreed with Hartlaub's revision of the genera 



of Pandeidae (Tiaridae), and he would certainly have approved my referring the 



species to that genus ; the numerous specimens of this species, in all developmental 



stages, contained in the second collection, have enabled me to give a thorough account 



of the development, (iii) Cosmetirella davisi is only briefly dealt with, because on a 



previous occasion (1932) I have given a thorough description of this species, based upon 



specimens in Mr Browne's collection procured during a visit to Berkhamsted in 1930. 



(iv) I have been able to describe the young stages and the rate of development of the 



tentacles in Phialella falklandica and Phialidiiim simplex, (v) In Willia mutabilis I have 



given a more detailed description of the tentacles, and I have been fortunate enough 



