118 GOÉS, KICTICULARIAN RIIIZOPODA OV THi: CARIBBEAN SEA. 



Syn. Amphistegina vulgaris, Lessonii d'Orb., 1826, Tabl. niétli., Ann. Se. Nut. 7, p. 304, 305; Mod. 40, 



98; t. 17, fiss- 1—4. 

 » gibbosa d'Oiih., 1839, Cuba, p. 120, t. 8, figg. 1—3. 



« Hauerina, mamillata, rugosa u'Orb.. 1846, For. teit. Vieune, p. 186, t. 12, figg. 



3—11. 

 » vulgaris Parker et Jones et Brady, . 186C, Crng. For.; Pal. Soc. 19, t. 2, figg. 



46—48. • 

 11 minuta Brady, 1876, Carbonif. and Perm. foramf.; Pal. Soc. 30, p. 146, t. 11, 



tig. 7. 

 » Campbelli, Aueklandiea Kärr., 1865, Por. Griinsandst. N. Zeeland.; Novara Reise, 



geol. Th. 1. 2, p. 84—85, t. 16, figg. 19. 

 ? M ornatissima Kärr., 1865, Griinsandst. N. Zeel.; Novara Keise, geol. Th. 1. 2, p. 85, 



t. 16, fig. 20. 



Orbiculiiia adiuica Ficht. et Moll. 



Tab. IX, figg. 304—307. 



This handsouie aod variable species presents itself in deep water promiscuously 

 ill botli its adunca- and »orlriculay^^oruis. The lattei' is for tlie most part flattened out 

 tu a singlefioored thin disc, that often shows a few broad radiating impressions on 

 both its sides. Those impressed bands are occupied by somewhat Avider subdivisions 

 or »chamberlets. 



A Peneropli-iorm variety is also inet with in company with the coininon forms. 

 It is impossible to distinguish it from some forms designated as Peneroplis jjroteus 

 d'Orb. from the West Indies, Peneropl. prisca Rss. from the tertiary strata and Pene- 

 ropl. planatus var. lasvigatus Kärr., also from the tertiary formation. 



Since no other true distinction between Orbiculina and Peneroplis has been stated 

 than the striation or plication of the surface of the latter, it would be inconsistent 

 with the notion of genus and even of species to distinguisli forms, which cannot duly 

 be entitled higher than as to rank of varieties. 



d'0ki5IGNY himself admits that »les Orbiciilines, pour nous, ne sont que des Péne- 

 roples a loges divisées (Hist. d. Tlle de Cuba Foraminif. p. 64).» On this accouut it 

 seems justiiiable to range »PenerojjUs^^ as a variety under Orbiculina or vice versa, as 

 the latter may be regarded as a higher developed Peneroplis. 



The striated form, in no way but in this feature diftering from young ö?'62aiZma-', 

 are also met with, but always scanty and in a pigmy state. 



Orbiculina adunca is very common also in deep water, particularly its orbicula- 

 forin, which attains a diameter of 6 mm. 



The simple and unstriated form is more rarely met with. 



By examing several specimens whole and in horizontal seetion 1 have satisiied 

 inyself that the outer chamberwalls are pe'rfora.ted with veritable pores of a middle 

 size, now pretty closely arranged and now more scattered. 



Figg. 304 — 305: quite young specimens. 



Figg. 306 — 307: peneropliform, unstriated Orbiculina ndunca. 



