138 . Transactions of the Society. 



Rhabdogonium carinatum, sp, n. (PI. IV, figs. 20-25.) 



The test is triangular in cross-section, and the orifice is stellate 

 and somewhat produced. The chambers are narrow and slightly 

 embracing, and each successive chamber increases very little in 

 height. The sutural depressions are arched. Each chamber is 

 carinate at its angles. Sometimes the carination is continuous. 

 The tests are transparent, and vary a good deal in outline. 

 Probably both the megalospheric and microspheric forms are 

 present. 



Ten occur ; one is very much malformed, and two are not cari- 

 nate ; these latter are probably immature. The specimens appear 

 to be closely allied to Chapman's BhaMagonium tricarinatum 

 d'Orbigny, sp., var. acutanguhim Eeuss, var. (Journ. Roy. Micr. 

 Soc, 1894, p. 159, pi. iv. fig. 8), and may prove to be nothing more 

 than a local form. I have two examples of this form from the 

 "Challenger" Station No. 185, Raine Island, one of which is 

 identical with my fig. 20, and which I submitted to the late Mr 

 Millett for his opinion. He wrote : " The clear shelled RhaMog- 

 onium is a splendid specimen, and you must figure it — Chapman 

 gives something like it from the Gault, he calls it acutangulum, but 

 1 doubt if yours is that species." 



I have also a specimen that I found in material received from 

 the U.S. Nat. Museum, marked " U.S. steamer ' Albatross,' St. 2150 ; 

 382 fms., near Old Providence Island." 



Fig. 25 is no doubt a young shell, and is somewhat similar 

 to Pieuss' B. globiferum, Sitz. d. k. Ak. Wiss. Wien., vol xl, 1860, 

 p. 201, pi. vii, fig. 6, and B. pygmmum, Denkschr. d. k. Ak. Wiss. 

 Wien, vol. xxv, 1865, p. 138, pi. ii, fig. 32, and B. 2)yg'}n6eum 

 (Pieuss) Terquem, Ess. Anim. Plage Dunkerque, pt. i, 1875, p, 22, 

 pi. 1, fig. 8. 



Marginulina d'Orbigny. 



Marginulina glabra d'Orbigny. (PI. IV, figs. 26-31, and PI. V, 



figs. 1 (?), 2, 3.) 



Marginulina glabra d'Orbigny, 1826, Ann. Sci. Nat., vol. vii, p. 259, No. 6, 



Mcdele, No. 55. 

 M. ])edtim d'Orbigny, 1846, For. Foss. Vien, p. 68, pi. iii. figs. 13, 14. 

 M. similis, d'Orbigny, 1846, For. Foss. Vien, p. 69, pi. iii, figs. 15, 16. 

 M. glabra, Flint, 1899, Eept. U.S. Nat. Mus. for 1897 (1899), p. 313, pi. Ix, 



fig. 1. 



One hesitates to add to the numerous figures of this species and 

 its varieties, but the specimens I have figured are interesting as 

 being recent examples, and I am bringing them all under the 

 above heading. Other tests are more characteristic of the species. 



.Fig. 26 is not far removed from 31. suhcrassa Schwager, 1866, 



