and Carpenteria monticularis. 173 



pi. xiii. figs. 19-22) I have described and figured the struc- 

 ture of the spheroidal form of Tinoporus vesicularts, Carp., 

 stating that it was " inexplicable " to me how Dr. Carpenter 

 could have adopted De Montfort's name " Tinoporus " for a 

 genus whose affinities are with Polytrema rather than with 

 Calcarina^ of which last De Montfort's Tinoporus haculatiis is 

 evidently a species. We have only to place the Red-Sea 

 variety, viz. Calcarina calcar, D'Orb., beside the Philippine 

 Tinoporus haculatus to instantly see the gradation of form 

 between T. haculatus and Calcarina Spengleri^ even if the sec- 

 tions of T. haculatus, as I have before stated, did not prove 

 this. The spines on all the Calcarina-\i\iQ Forarainifera are 

 mere prolongations of the marginal cord and septa combined, 

 both of which are the same in structure, as may be proved 

 by the latter being successively developed (in front of the last- 

 formed chamber) from the marginal cord. Thus the spines, 

 no doubt, possess the same kind of canal-system as that of 

 Operculina, &c. ; but while in Calcarina calcar the marginal 

 cord opposite each chamber sends forth a spine, and the three 

 or four last-formed chambers are visible on the basal side, as 

 in Calcarina Spengleri, there are fewer and larger spines in 

 Tinoporus haculatus, where, too, the three or four last-formed 

 chambers are concealed from view by surface-structure. 



Now Tinoporus vesicularis, Carp., has no distinct trochoi- 

 dal spire of chambers, and nothing like a marginal cord ; 

 hence it has no canal-system, nor has it, as I have before stated, 

 the peculiar pseudopodial canal-system of Polytrema ; in short, 

 it is nothing but a mass of cells growing exogenously in a 

 laminar form from a more or less confused group in the centre, 

 which has no communication with the exterior excepting 

 through the foraminated plates of the respective cells. 



Hence, to adopt the name of " Tinoporus " for a totally 

 different genus of Foraminifera like that of Tinoporus vesicu- 

 laris, -Carp., is a mistake, which leading to confusion in- 

 duces me to propose in its stead that of " Gypsinaj''' whence 

 we get Gypsina vesicularis, Carp., with the spheroidal variety 

 illustrated irf my paper of 1877 (/. c). 



This brings us to Gypsina melohesioides, which is but my 

 Poly trema planum in a more extended form. Hitherto all the 

 Foraminifera have been characterized by their individuality. 

 Whole beds of Operculina and Glohigerina respectively, ex- 

 tending for many square miles together, present nothing 

 beyond single and separate individuals of these two genera as 

 plentiful and distinct as grains of sand; but in Gypsina 

 melohesioides they are all united together into a continuous 

 incrustration extending over several square inches ; in fact 



