34 HENRY B. BRADY. 



almost every fragment of shell or stone presenting a surface 

 favorable to their growth. It is rarely, however, that the 

 tests are even approximately complete or perfect, and the pri- 

 mordial chamber being generally the missing portion they 

 have hitherto been passed over, under the supposition that 

 they were the tubes of adherent annelids. This imperfection 

 arises from the fact that the primordial chamber is seldom 

 completely attached to the body on which the remainder of 

 the test is adherent. The tubular portion of the test is of 

 indefinite length and always seeks some solid basis to spread 

 itself upon, in the absence of which it is occasionally found 

 in little masses formed of irregular coils adherent to each 

 other. The bulbous end is often quite free, projecting above 

 the remainder of the test, from which it does not otherwise 

 differ in external characters, except that it is of a darker 

 reddish-brown colour. 



Hyperammina vagans differs from both H. elongata and 

 H. ramosa in its parasitic habit ; from the former also in the 

 great length and tortuous course of the tubular portion, and 

 from the latter in the simple unbranched contour of its 

 extensions. There is only one Foraminifer, so far as I know, 

 with which it is at all likely to be confounded, namely, 

 Wehhina clavata, P. and J., but the primordial chamber in 

 that species is a simple, adherent, tent-like, shelly dome, and 

 the tube a semi-cylindrical covering, neither of which has 

 any floor proper to itself. 



There is a fossil organism, occasionally met with in 

 palaeozoic limestones, of considerable interest in connection 

 with this species. It consists of rounded masses of finely 

 arenaceous tubes folded irregularly backwards and forwards, 

 or otherwise coiled, so as to form little bundles. My friends. 

 Prof. H. A. Nicholson, and Mr. R. Etheridge, jun., have re- 

 cently called my attention to some of these, which exist in 

 large numbers in the Silurian rocks of Girvan in Ayrshire, 

 and they will, I believe, be described in their forthcoming 

 'Monograph of Girvan Fossils,' under the provisional generic 

 term Girvanella. When the time comes for treating the 

 •' Challenger" Rhizopoda in detail, I shall be able to give 

 drawings of specimens of Hyperammina vagans, which 

 scarcely differ from the palaeozoic fossil except in their some- 

 what larger size. 



For the most part H. vagans is a deep-sea species, the 

 finest specimens being from two dredgings in about 2000 

 fathoms, one in the North Pacific, the other in the South 

 Atlantic, but it occurs also at smaller depths, especially in the 

 North Atlantic. 



