352 REV. O. p. CAMBRIDGE ON NEW SPIDERS. [Juiie 5, 



While in the embryonal or cartilaginous stage, both " pleurapo- 

 physial " or iliac (ib. ^7) and " haemapophysial " or pubic (ib.^a) 

 sustainers of the developed, and in Fishes fin-like, "appendage" 

 of such pelvic arch are continuous with the primitive " bar " or 

 plate (bp, basipterygium). But if they are so evolved as secondary 

 and subordinate members, their subsequent ossification exemplifies 

 their claim as independent or distinct elements of their vertebral 

 segment. 



Lepidosiren and Polypterus retain the later segmentation of the 

 "basipterygium," with feeble rudimentary indications of rays in the 

 narrow skin-fold which it supports. The proximal piece of the fin- 

 skeleton of Ceratodus, like that of Lepidosiren, answers to the 

 basipterygium = metapterygium, not to the mesopterygium, which, 

 as Balfour shows, is a secondary character, and is not developed 

 in certain Fishes, e. g. Scyllium. 



I cannot conclude without quoting the last letter with which I 

 was favoured by my friend : — 



" Trinity College, Cambridge, 

 Dec. 7th, 1881. 

 '' Dear Professor Ovfen, 



" I am much obliged to you for your kind note about my paper 

 on the ' Development of the Paired Fins.' I accept the justice of 

 your criticism on my use of the term ' girdle.' I used the term 

 merely because it was a term in common use, and must plead guilty 

 to never having troubled myself about its derivation \ I shall, 

 however, in future use the expression ' arch ' instead. 



" Very sincerely yours, 



" F. M. Balfour." 



2. On some new Genera and Species of Spiders. 

 By the Rev. O. P. Cambridge, M.A., C.M.Z.S., &c. 



[Eeceived AjDril 23, 1883.] 



(Plates XXXVI. & XXXVII.) 



Eight Spiders, representing, as it appears to me, as many new 

 genera, are described and figured in the present paper from examples 

 in my own collection. Two of them belong to the family Therapho- 

 sidse, one to the Drassidse, and tlie remaining five to the Thomisidse. 

 Three species are from Ceylon, three from Caifraria, one from New 

 Zealand, and one from California. For the Ceylon species I am 

 indebted to the late Mr. G. H. K. Thwaites ; for those from Caffiaria 

 to Mr. Mansel Weale ; for the New-Zealand species to Captain F. W. 



1 "G-iKDLE — Belt or Zone. Any thing drawn round the waist and tied or 

 budded." — Johnson. ■ 



The " pelvic arch " is inverted ; its piers, as a rule, are based on the sacrum : 

 the "pectoral arch" is inverted, and its piers, save in most Fishes, are free. 



