190 Rev. O. P. Cambridge on some 



The ascertained relative duration of the three periods above 

 defined in the artiodactyle mammals most nearly approaching 

 the Hippopotamus amphibvus in size, supports the conclusion 

 here endeavoured to be drawn from what could be ascertained 

 of these periods in the captive male in the Gardens of the 

 Zoological Society of London, viz. that the duration of its life 

 under these circumstances must be that, or nearly that, of the 

 individuals of the species in their native land and wild state, 

 which may accordingly be set down at or about 30 years. 



It is but due to the responsible officers in charge of the 

 exotic animals in that noble establishment, to bear grateful 

 testimony to their successful treatment, and to their exact ob- 

 servations and records of phenomena essential, to the advance- 

 ment of the science of Natural History. 



British Museum, July 20, 1879. 



XXIV. — On some new and rare British Spiders, with Cha- 

 racters of a new Genus. By the Rev. O. P. Cambridge, 

 M.A., C.M.Z.S., &c. 



[Plate XII.] 



Since my last communication on British Spiders (Ann. & 

 Mag. Nat. Hist. Feb. 1878, ser. 5, vol. i. p. 105, pi. xi.) I 

 have been enabled, through my own researches and the kind 

 assistance of several friends and relatives, to add thirty-nine 

 species to the list of those then known to Great Britain and 

 Ireland. Fifteen out of the thirty-nine appear still to be 

 undescribed ; twelve others have not hitherto been recorded as 

 British, though known on the continent of Europe ; and the 

 twelve remaining species have lately been described, either 

 as new to science or to Britain, in Part I. of " The Spiders of 

 Dorset," published in the ' Transactions of the Dorset Natural- 

 History and Antiquarian Field Club ' for 1879. The fifteen 

 new species, above referred to, are described in the follow- 

 ing pages ; and several of them are figured in the accompanying 

 Plate. A list is also appended of those spiders not before 

 recorded as British, and of the others mentioned above as 

 described and recorded in " The Spiders of Dorset." 



Several of the species included in the total (484) of British 

 spiders recorded up to the time of the publication of my last 

 communication (February 1878) have since been ascertained 

 to be synonymous with others previously known. The num- 

 ber now considered to be British, so far as they are known up 



