290 HENRY B. BRADY. 



are not uncommon, but they occur, as often as not, two or 

 three to a shell, and they either have abrupt angular edges, 

 indicative of accidental fracture, or they are found at spots 

 where the shell has been previously worn very thin. It 

 must be remembered that the nature of the perforations 

 which already exist in the shell-wall is one peculiarly favor- 

 able to the formation of larger orifices by abrasion or pres- 

 sure. The matter, perhaps, is not one of very great conse- 

 quence, seeing that it is admitted on all hands that a general 

 aperture is not an essential or even a usual characteristic 

 of Orhuliiia. In Cymhalopora under similar circumstances 

 the general aperture is wanting, and a series of large per- 

 forations, in addition to the normal minute ones, takes its • 

 place, and there are other types of Foraminifera that have a 

 number of conspicuous pores on the face of the terminal seg- 

 ment when it is of abnormally large size. It appears to me 

 clear, therefore, that of the two sets of perforations in Orhu- 

 Una, the larger ones stand in lieu of the aperture or aper- 

 tures of the normal Globigerine shell. 



Gl. {Orhulind) neojurensis , Karrer (' Sitzungsb. d. k. Akad. 

 Wiss.,' vol. Iv, p. 368, pi. 3, fig. 10).— The surface of the 

 test in many species of helicoid QlobigerincB often bears a sort 

 of honeycombed or reticulate ornamentation, best observed 

 in specimens collected at the surface of the sea. This pecu- 

 liarity is seldom met with in the Orbuline varieties, but Dr. 

 Karrer has described and figured such a specimen amongst 

 other fossil microzoa from the " White Jura " of St. Veit, 

 near Vienna, under the name above quoted. Dr. Wallich 

 has a drawing of a similar shell in his memoir on the 

 ''North Atlantic Sea-bed," pi. 6, fig. 9, and examples of 

 the same form have been met vvdth both by the Rev. A. M. 

 Norman and myself in recent Glohigerina-oozQ ; but, both in 

 the recent and fossil condition, the variety is exceedingly rare. 



Under the name Glohigerina hilohata (' For. Foss. Vien.,' 

 p. 164, pi. 9, fig. 11 — 14) d'Orbigny has figured what 

 appears to be only a double Orhulina with slightly reticulated 

 surface. Monstrosities of this kind are by no means uncom- 

 mon wherever Glohigerin<B abound, and sometimes, though 

 less frequently, specimens with two supplementary chambers, 

 one on each side of the parent-cell, may be met with. On 

 these grounds it does not seem worth binomial distinction. 



