205 



ingly, animals poisoned with strychnia try to move in the ordinary 

 way, but every attempt brings on a tetanic fit, so that it is plain that 

 the spinal cord may also be excited by the brain to its peculiar 

 actions. 



6. If the tetanus produced by strychnia has been strong, the 

 muscles are less irritable and pass much sooner into the state of 

 cadaveric rigidity, which is very strongly marked, and seems to last 

 longer than it generally does. The same early onset of rigidity may 

 be observed in animals killed by tetanus excited by electricity. 



X. " Researches on the Foraminifera." Part II. By WILLIAM 

 B. CARPENTER, M.D., F.R.S., F.G.S. &c. Received June 19, 



1856. 



(Abstract.) 



In the pursuance of his plan of minutely examining certain typical 

 forms of Foraminifera, for the purpose of elucidating their history as 

 living beings, and of determining the value of the characters they 

 present to the systematist, the author in this memoir details the 

 results of his investigations on the genera Orbiculina, Alveolina, 

 Cycloclypeus, and Heterostegina. 



The genus Orbiculina has long been known, through its preva- 

 lence in the West Indian seas, which causes its shells to abound in 

 the shore-sands of many of the islands of that region. These shells 

 present great varieties of form, and have been ranked under three 

 distinct species ; but M. d'Orbigny has correctly inferred, from a 

 comparison of a large number of specimens, that their diversities of 

 form are partly attributable to differences in the stage of growth, 

 and partly to individual variation, so that all the Orbiculince of 

 Cuba, the Antilles, &c., are referable to but one specific type. Of 

 the essential features of its structure, however, he would seem to be 

 quite ignorant ; since he ranges Orbiculina in a distinct order from 

 Orbitolites, to which it is very closely allied. This alliance was 

 first pointed out by Prof. Williamson, whose account of the structure 

 of Orbiculiua, though defective and erroneous in certain points, is 

 nevertheless correct in the main. 



The author has had the opportunity of examining not merely a 



VOL. VIII. S 



