108 GOÉS, RETICULARIAN KHIZOPODA OF THE CARIBBEAN SEA. 



In »Microgeology» by Ehrenberg t. 35, B, lig. 7 there is represented a young 

 form called Spiropleurites nehulosus, which probably belongs to this species. From 

 Discorb. valvulata it differs only in closer and finer poration, not yellowish shell and 

 its pigmy size. 



Fig. 266: spire-side. 



Fig. 267: side-view; 268: apertural side. 



Syn. Rosalina Berthelotiana d'Orb., 1844, Hist. iles Canaries for., p. 135, t. 1, figji. 28 — 30. 



Diseorbina Bertheloti Brady, 1864, Rhizop. Shetl.; Träns. Lin. Soc. 24, p. 469, t. 48, fig. 10. 

 » Parisiensis var. Berthelotiana Paiik. et Jones, 1865, North. Atl. and Aret. Oc; Phil. 



Träns. 155. 1, p. 387, t. 16, figg. 26 — 27. 

 PRosalina eoneava Ess., 1854, Kreide. Ostalpen; Wien. Ak. Dksolir. 7, p. 70, t. 26, fig. 3. 



Diseorbina vesicul.iris Lmk. var. elegans d Orb. 



Tab. VIII, figg. 269—271. 



On the authority of Messrs Parker and Jones we consider this form as ideiitical 

 with Rosalina comjjlanata d'Orb. (For. Bass. tert. Vienne p. 176, t. 10, figg. 13 — 15) 

 notwithstanding this, as also Ros. complanata Rss. (Neue For. österreich. tert. Beck.; 

 Wien. Akad. Dkschr. 1. 1, p. 373, t. 47, fig. 5) has its spire less invested by the last 

 convolution. Our form is remarkable for the great symmetry of both its sides, which 

 are hardly distingnishable from each another; both being provided with a deep and 

 narrow umbilicus. The aperturale fissure is verj' inconspicuous. The »valve» or »astral 

 lobes» are represented by 2 or 3 small scalelike outgrowths partlj' covering the open- 

 ing of the umbilicus; the shell surface is somewhat polished. 



Where is not for the yellowish tint of the shell-substance in transmitted light 

 and for the characteristic size and disposition of the pore-canals one would hardly be 

 able to recognize this form as a Diseorbina, but would rather refer it to Planorbulina. 



It is not coinmon in the chalk-ooze, and is always found in a pigmy state. 

 Fig. 269: spire-side. 

 Fig. 270: side-view. 

 Fig. 271: apertural-side. 



Syn. Anomalina elegans dOrb., 1826, Tabl. meth., Ann. Se. Nat. 7, p. 282; Mod. N:o 42. 



Spirillina vivipara Ehrenb. 



Tab. VII, fig. 272. 



The pores of this very simple rhizopode are variable in closeness of arrangement. 

 FuUgrown specimens have them pretty close and of the same size as Planorbulina Ungeriana. 

 Very small ones are not easily distinguishable from young Trochamminaä incertfe. 



It is very common; particularly in the chalk-ooze, seldom attaining in diameter 

 more than 0,20 mm. 



