KONGL. SV. VKT. AKADKMIKNS II ANDI.INGA U. BAM) 26. N:() 2. 8/i 



Var. Eudoxia A. S. (1875). — V. linear, with roniulod ends. L. 0,07 to Ojoy.'s; B. 0,017 to 

 (),(t2 2 mm. CostiC 6 to 7 in O.oi mm. Furrows narrower, than on tlie t.v})(^ — Nav. nicditordin a 

 A. S. N. S. \). PI. n f. 10. S(ir. Kudoxia A. S. Atl. VJll f. 10, LXX'f. 71. 



Marine: Morocco! Balearic Ishiiuls! Red Sea! Bab el maiuleb! Madagascar! Ceylon! (Jala- 

 pagos Islands! Monterey (Atl.). Fossil: Szakal, Hungary! 



Var. EiujcHia A. S. (1875). — V. with subcuneate ends. L. 0,or); B. 0,017 mm. Costa; 7 

 to 8 in 0,01 mm. — Nav. Eugenia A. S. Atl. VIII f. 44. 



Marine: Ceylon (Leoduger Fortm.) Macassar Straits! Campeaehy Bay (Atl.). 



There is, so far as I can see, no specific distinction between the above forms, whic^h I I'cgard 

 as belonging to D. contigna. They are perhaps all only smaller, and corroded, forms of ]). (/tnniuitd. 



lo. D. circuinnodosil Brun. (1891). — V. very convex and thick, linear, with broad, rounded 

 ends. L. 0, 1; B. 0,()2;i mm. Central nodule short and broad; its horns divergent at the nodule. 

 Furrows very broad. Costa; 7 in 0,oi ram., continued across the furrows as rows of three large 

 puncta. — Nav. circumn. Brun. Esp. n. p. 38 PI. XVI f. 2. 



]\larine: .Japan, fossil (Brun Coll.)! 



l(i. 1). Letoiirneuri Cl. N. Sp. — V. elongated, very slightly constricted in the middle, with 

 broad, rounded ends. L. 0,07; B. O.o2;i; at the constr. 0,02. Central nodule elongated quadrate; its 

 horns nearly parallel. Furrows very broad. Costte 9 in 0,oi mm. almost parallel, continued 

 across the furrows, smooth. — PI. I f. 18. 



Marine: Col umbo, Ceylon (Letourneur Coll.)! 



17. D. muscseforniis (Irun. (1875). — V. gently constricted in the middle, with cuneate 

 ends. L. 0,07 to 0,095; B. 0,o3 to 0,u4 at the constr. 0,024 to 0,o37 ram. Central nodule quadrate, 

 with approximate, scarcely divergent horns. Furrows ',<, to '3 as broad as the valve. Costtt 4 

 to 7 in 0,0 1 mm., with faint continuations across the furrows. 



Var. placida A. S. L. 0,o9 mm. Costw 4 to 4,5 in 0,oi mm. — Nav. placida A. S. Atl. 

 CLXXIV f. 2. 



Marine: (^ralapagos Islands! San Pedro Calif, fossil (Kinker Coll.)! Uamaru New Zealand, 

 fossil (Atl.). 



Var. genuiita Cl. — Costai 7 in 0,oi mm. — Nac. iintsca'furiii. A. S. Atl. XIII f. 42, 47. 



Marine: Campeaehy Bay! Java! 



Var. coustrlcta Grun. — Ends rounded. L. 0,05 to 0,o6; B. 0,oi8 to 0,oi9 at the constr. 

 0,0 13 to 0,0 15 mm. Costfe (j to 7 in 0,oi mm. — Nav. constricta GrRUN.? A. S. Atl. XII f. G5; 

 LXIX f. 42. 



Marine: Balearic Islands! Sansego (Atl.), Seychelles (Van Heiirck Coll.)! Madagascar! Suin- 

 bava (Kinker Coll.)! Japan (I>eby Coll.)! Leton Bank (Atl.). 



Var. piisiUa Cl. — V. slightly constricted. L. 0,02; B. 0,oio mm. Costiv 9 in 0,01 mm. 



Marine: Galapagos Islands! 



This form is doubtful as a sj)ecies, having \'ery much the appearance of strongly corroded 

 valves of other species as 1). Bci/richiaHa and allied forms. (tRUNOW mentions a form from the 

 Caspian Sea in length O.o.ik mm. and with 12 costie in 0,oi mm., which seems not to l)eloiig' to 

 I), maacfeformis. 



18. D. coustricta Grun. (18()0). — V. gently constricted in the middle, with subcuneate 

 ends. L. 0.06 to 0,15; B. 0,o2.i to 0,o:!, at the constr. 0,o2 to 0,025 mm. Central nodule quadrate, 

 its horns parallel, a])proximate. Furrows very broad. Costse 7 to 8 in 0,oi mm., very faint on 

 the furrows, radiate at the ends. — Nav. con.'ifricffi. Grun. Verb. I860 p. 535 PI. Ill f. 18 (according 

 to V. H. T 103). Nar. Musca DoNK. B. D. p. 50 PI. VII f. t> (1873). .Y«/-. Bonhimi A. S. N. S. 

 D. PI. I f. 12 (1874); II f. 8. Atl. XII f. »i3, (U. 



Mai'ine: Finmark! Xorth Sea! Balearic Islands! Cevloii! Florida! 



