REPORT ON THE FOR AMINT PER A. 
203 
This is a pretty variety, resembling Cornuspira involvens in its concave shape and 
rounded peripheral edge, but characterised by the somewhat peculiar reticulated surface- 
ornament above described. It has only been found in one locality, Station 185, off 
Raine Island, Torres Strait, 155 fathoms. 
Peneroplis, Montfort. 
Nautilus, pars, Linne [1767], Forskal, Spengler, Gmelin, Batsch, Fichtel and Moll. 
Spirolina, Lamarck [1804], Blainville, Defrance, d’Orbigny, Michelotti, Costa, Karrer, &e. 
Spirolinites, pars, Lamarck [1804], Blainville, Defrance. 
Peneroplis, Montfort [1808], Blainville, d’Orbigny, Roemer, Reuss, Carpenter, Williamson, 
Parker and Jones, Karrer, Moebius, &c. 
Cristellaria, pars, Lamarck [1816]. 
Spirula, Blainville [1825]. 
Dendritina, d’Orbigny [1826], Reuss, Parker and Jones, Karrer, &c. 
Coscinospira, Ehrenberg [1839]. 
The genus Peneroplis comprehends a large and multiform series of porcellanous 
Foraminifera, characterised by polythalamous shells, the segments of which are arranged 
to a greater or less extent in a planospiral manner, the cavities of the individual 
chambers being entire, that is to say, not subdivided into chamberlets by shelly 
partitions. These, however, are the only features common to the whole group. The 
shells may be lenticular in contour, complanate, or . crosier-shaped ; the surface, though 
usually striate, may be smooth; and the aperture may be porous, or irregular and dendritic. 
The minor characters on which such conditions depend, though they have been made the 
basis of generic and specific definitions, are too variable to be of any distinctive value. 
The shell is imperforate, and its texture even and homogeneous; but both the inner 
and outer surfaces are often marked with minute pits (PI. XIII. fig. 23), which bear some 
external resemblance to the tribulation of the shell- wall in the hyaline Foraminifera, 
but which are easily shown to be mere superficial depressions. 
As all the known recent forms of Peneroplis are referrible to a single zoological species, 
the further description of their morphological characters may be deferred. Of certain 
modifications of the type, which exist only in the fossil condition, I am not in a position 
to speak. In M. Munier- Chaim as’ collection there are specimens, of early Tertiary age, 
which appear to be specifically or perhaps sub-generically distinct, so far as such terms 
can be properly used with reference to closely allied Foraminifera ; but as these have not 
yet been described, they are outside the scope of the present notice. 
An elaborate account of the genus Peneroplis has been given by Dr. Carpenter in the 
Philosophical Transactions for 1859, and again in the Introduction to the Study of 
the Foraminifera (p. 84), and ip both memoirs the structural details are illustrated by 
Mr. George West’s excellent drawings. 
