338 MESSES. T. B. JONES AND E. CHAPMAN 



are sometimes giyen oiF. TLe swollen segments are normally 

 subdivided in the interior by septa, which in some cases extend 

 across from wall to wall, but in others are not quite continuous, 

 and so placed as to form a valvular opening. In the attached 

 forms the swollen portion of the test is more, definitely Poly- 

 morphine both on the exterior and in the interior. The one or 

 more apertures in the forms that are free are circular, being 

 formed by the open end of the calcareous stolon-tube. In the 

 attached forms, the apertures are usually formed by the pro- 

 tracted terminations of the stolon-tubes, and are semicircular in 

 outline where the entire test is adherent to the foreign body. In 

 this point they closely resemble the terminal apertures of the 

 Arenaceous genus Saffenella. The surface of the test in HamuUna 

 is sometimes smooth, especially in the attached forms ; but more 

 frequently the surface is either hirsute, strongly prickly, or 

 tuberculate. An instance is known where Bamulina has been 

 found within the chambers of another Foraminifer ; also on 

 and in fossil Echinoderm-tests, traversing the ambulacral pores ; 

 but this cannot be true parasitism. 



With regard to isomorphous forms resembling JRamulina in 

 those other groups of the Foraminifera which are characterized 

 by a difference of test- structure, it is instructive to note the 

 comparable forms of Nubecularia tihia, Jones & Parker, JSf. luci- 

 fnga, Defrance, aod N. nodulosa. Chapman, in the Porcellanous 

 group. In the Astrorhizidcs of the Arenaceous group we note 

 the close resemblance shown in AscJiemonella catenata (particu- 

 larly fig. 3 of pi. xxvii. in Brady's Monograph, about which 

 Canon Norman remarks, in a letter, that Dr. Brady has here 

 confused two types under one name). The singular form of 

 Sagenella is also strongly suggestive of an attached cervicorn 

 Mamulina, although there is no distinct initial series in the figured 

 examples, pi. xxviii. figs. 14, 15. 



As the result of a systematic examination of all the published 

 varieties of Ramuliiia, as well as many specimens from the Chalk- 

 detritus (Chalk-marl) of Charing, Kent, the Gault of Polkestone, 

 and other material of our own collecting, we have come to the 

 conclusion that Mamulina, as at present known, can be specifically 

 divided into five well-marked types, as described further on. 

 The known specimens are here arranged under their specific 

 heads according to date of publication. 



The following catalogue raisonne of the published and best 



