122 GOES, RETICULARIAN RHIZOPODA OF THE CARIBBEAN SEA. 



Vertebralina sulcata Rss., 1863, Oberburg in Steiermark; Wien. Ak. Dkschr. 1. 23. i, p. 9, 



figg. 2-6. 

 Articulina compressa Rss., 1863, Mainzer Becken; Leonh. u. Bronn. Jhrb. 1853, p. 673, t. 9, 



fig. 3. 

 Vertebralina striata WILLIAMS., 1858, llec. Brit. For. p. 90, figg. 197198. 



CARPENTER, 1862, Introd. t. 5, figg. 1722, 25. 



PSpidostomella glotaulifera COSTA 1854, Pal. Nap. 2, t. 27, fig. 27 (an Miliolina). 



Miliolina seminulum LIN. 



Tab. IX, figg. 319355; Tab. X, figg. 356360. 



As the type for this species, - - the varied forms of which have been ranged 

 in a bewildering assemblage of species, founded even on the most trifling and 

 inconstant differences , could properly be chosen the oblong, more or less com- 

 pressed, usually smooth form. The relation of the length of the different dia- 

 meters to each another is subject to an infinity of variations, whence a mass of varietal 

 modifications originates (besides all those, resulting from different arrangement of the 

 chambers) from produced oblong to the disciform Triloc. orbicularis ROM. The shape 

 of the mouth is also very variable: if the last chamber is provided with a long tubi- 

 form neck, the mouth is round with a very reduced tongue, while a flat and broad 

 neck usually has a narrow, produced mouth with a flat, often raised tongue; the 

 thick inflated forms have broad mouth and valvelike tongue somewhat resembling that 

 of Mil. ring ens. It is often finely agglutiriant, and is one of the commonest rhizopodes 

 in the chalk-ooze, particularly its pigmyforms, Triloc. oblonga MONTAG. and D'ORBIGNY. 



1. Var. scapha D'ORB. This variety has a fine porcellaneous lustre and a nearly 

 semilunar aperture. It seems in some way closely allied to Mil. ringens. It has a 

 a lenticular, somewhat marginated shape. When the edge of an older chamber occa- 

 sionally becomes turned outside on the flat side of the shell, its shape approaches to 

 HtriangularisB D'ORB. Such a form has been designated as Quinqueloculina Lamarckiana 

 D'ORBIGNY. 



It is common both in the coralline-gravel and the chalk-ooze. 



2. Var. triangularis D'ORB. is scarcely deserving to be ranked as a distinct 

 variety, since its features seem to be quite accidental and inconstant. It is not seldom 

 3 to 6 keeled or even winged as in Quinqueloculina Candeiana D'ORB. When the edges 

 or the keels arid ridges become truncate, the form has been called Ferusaci, quadri- 

 latera D'ORB. It is often finely agglutinated. 



Occurs chiefly in the coralline-gravel. 



3. Var. trigonula LMCK. seems to be a more distinct form; Prof. WILLIAMSON 

 has also ranked it as a distinct species. Our form is quite trigonal, sometimes with 

 sharp edges and flat sides. It has a porcellaneous lustre, but its intimate shellstructure 

 is not homogeneous, either because of some slight admixture of agglutinated particles 

 or because of a spongious texture. 



It is (infrequently met with on our terrain. 



