dredged up from the Gulf of Manaar. 445 



by foraminated interstices variable in form and separated from 

 each other by reticulated lines of translucent shell-substance, 

 Avhich is frequently very prominent and transparent at the 

 angles, forming- the ends of a columnar structure in which the 

 cells are united laterally by holes of intercommunication, and 

 above and below by a foraminated plate, like that of the 

 " interstice " on the surface, through which the innermost cell 

 thus indirectly obtains communication with the exterior. 

 No oral aperture. No canal-system. 



Such are the characters of this genus, which is founded 

 on the species, Gypsina melobesioides, that I described in 

 1877 ('Annals,' vol. xx. p. 172) ; but as the facts leading 

 to it were communicated at intervals, and are now confirmed 

 by specimens of each of the species contained in the genus, 

 from the Gulf of Manaar, I will briefly recapitulate what has 

 been stated. 



When I showed, in March 1877 (' Annals,' vol. xix. p. 215 

 et seq.), that Tinoporus vesicular is, Carpenter (Introduction, 

 p. 224, pi. xv. figs. 1-3) , had " no generic affinity with De 

 Montfort's T. baculalus" I was not aware of the existence of 

 the incrusting species to which I gave the name of Gypsina 

 melobesioides {op. et loc. cit.) ; but seeing that the structure of 

 the latter was identical with that of Dr. Carpenter's Tinoporus 

 vesicularis, I at once realized the necessity of changing the 

 generic name of the latter also to Gypsina, thus making it 

 G. vesicularis, Carpenter {ibid.). Had Dr. Carpenter, instead 

 of applying De Montfort's name of Tinoporus {T. baculatus 

 being a Galcarina), given it a new name, then this might 

 have been used instead of the one I have proposed. 



Further, I observe that the Foraminifer to which I gave 

 the name of " Poly trema planum " (' Annals,' 1876, vol. xvii. 

 p. 211, pi. xiii. figs. 18, 19), and which came from the south- 

 west coast of Australia, was a specimen of Gypsina melo- 

 besioides ; hence its name also will have to be suppressed, at 

 the same time that another locality is thus added to those 

 already noticed of G. melobesioides, viz. the Mauritius, the 

 West Indies, and, lastly, the Gulf of Manaar. 



Gypsina melobesioides, sp. 1877. 



There are four specimens of this species among the dredg- 

 ings from the Gulf of Manaar, two of which nearly cover 

 globular nodules of Melobesia, respectively half an inch in 

 diameter, with an incrustation about l-48th inch thick and 

 twelve cells deep. The other two are also on the surface of 

 similar nodules, but not so extensive. The incrustation 

 spreads itself continuously over whatever irregularities may 



