248 Mr. J. Miers on Ephedra. 



inches. 



Total length, mouth open IS^V 



„ „ mouth closed 12 



Height hetween vent and anal fin 4-f 



Head, length, mouth open 5 



„ „ mouth closed 3py 



Eye, diameter 1-j^ 



Eyes, distance apart l^j- 



Nostrils, distance apart T 4 ^ 



Mouth, when open, 1-^ by 1£ 



Premaxillar} r , length of pedicel 2^ 



Dorsal, length of base of spinous portion .... 2 



„ „ „ soft portion 3\ 



,, length of third spine 1£ 



Pectorals, length \h 



, , distance behind anterior margin of eye 2fy 



Ventrals, length 3 



Anal, length 3^,- 



,, height posteriorly 1-j 1 ^ 



Tail, height at middle ^ 



Caudal, length 1^ 



„ span 3^ 



XXVII.— On Ephedra. By John Miers, F.R.S., F.L.S. &c. 



[Continued from vol. x. p. ] 40.] 



The long interval that has elapsed since the appearance of the 

 former part of this paper demands a word in explanation. When 

 that portion was ready for the press, I was charged by the Go- 

 vernment of Brazil with duties arising out of the International 

 Exhibition, which required my undivided attention for many 

 months ; and it is only now that I am able to complete the fol- 

 lowing description of all the South- American species of Ephedra 

 known to me. 



In the mean time Dr. Hooker's memoir on Welwitschia has 

 appeared in the Linnean Transactions, which renders it incum- 

 bent on me to reconsider my former views concerning Ephedra. 

 That memoir will claim attention from every botanist, not only 

 for the careful description of the structure of this remarkable 

 plant, but for the admirable manner in which the elaborate 

 details of its analyses are illustrated; and it is fortunate for 

 science that Df. Hooker had at his command ample materials for 

 the investigation. For the present purpose it will be necessary 

 to refer only to such points in that memoir as may relate to 

 Ephedra. 



In the absence of the smallest information concerning the 

 female flower and the ovary of Ephedra, and with the knowledge 



