KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 101 



nating with double rows of somewhat coarse piincta (8 to 11 in (),oi mm.). ■ — Nav. expletu A. S. 

 Atl. LXIX f. 7, 8. 



Marilie: Zanzibar! Celebes (Atl.), Society Islands! 



This form diifers from var. Fandura by its shorter, less constricted valves. 



Var. Didelta Cl. — V. slightly constricted, with almost triangulär segments. L. O, oss; 

 B. 0,04; at the constriction 0,o28 mm. CosttE 8 in 0,oi mm. — Pl. II f. 8. 



Marine: Sumbava (Kinker CoU.)! 



Var. suheUiptica Cl. — V. elongated, not at all, or very slightly, constricted. L. O.is; 

 B. 0,052. Costfe 3 to 4 in 0,oi mm. alternatiug with double rows of coarse puncta, about 8 in 0,ui 

 mm. — Pl. II f. 11. 



Marine: South America, fossil! Macassar Straits (corroded form with 4 to 5 costte in 0,oi 

 mm. in Grove Coll.)! Galapagos Islands (perfectly elliptical form. L. O, os; B. 0,04 mm. Cost;i=. 5 

 in 0,0 1 mm. Ocelli not distinot). 



Var.? Pandurella Cl. — V. strongly constricted with subelliptical segments. L. O, oss to 

 0,075; B. 0,011 to 0,022; at the constriction 0, 007 to 0, 013 mm. Costce 8 to 9 in 0, 01 mm. alter- 

 uating with double rows of puncta, about 20 in 0, 01 mm. Pows of ocelli indistinct. — Pl. II f. 9. 



Marine: Indian Ocean (Deby Coll.)! China! Galapagos Islands! 



This form resembles in all respects the var. Fandura, but is much smaller and has closer 

 costse. As I have not seen any rows of ocelli I am doubtful whether this form is to be regarded 

 as belonging to this group; nevertheless it is related to the var. Fandura as the var. s'US2)ecta to 

 the var. separahilis and the var. Dirhonibus to the var. multicostata. 



B. Forms tvith moderatély vide Innulce. 



Var. separahilis A. S. (1875). — V. gently constricted with elliptical segments. L. O.os to 

 0,16; B. 0,033 to 0,05; at the constriction 0, 026 to 0, 032 mm. Costte 5 to 6 in 0, 01 mm. Lunulte 

 narrow. — Nav. Crabro Gkev. M. J. V. p. 7 Pl. III f. 11. Nav. Grevillei Donk. B. D. p. 47. 

 Nav. separahilis A. S. Atl. XI f. 3, 5, 6, 7, 10, 17. — N. Crabro var. Japonica A. S. Atl. 

 CLXXIV f. 4? 



Marine: Pelew Island (Atl.), Singapore (Deby Coll.)! Puerto Caballo (Atl.), Campeachy Bay 

 (Atl.), Trinidad (Grev.). 



This form is intermediate between var. Fandura and var. multicostata. 



Var. hiingarica Cl. — V. elliptical, not constricted. L. 0,o6; B. 0, 03 mm. Row of ocelli 

 marginal, not bent toward the central nodule. Costee. 5 in 0, 01 mm. Lunulse narrow. — Pl. Il f. 10. 



Marine: Szåkal (Hungary, fossil)! Galapagos Islands! 



Var. gloriosa Brun (1891). — V. slightly constricted, vith tongue-shaped segments. L. 0, 11 

 to 0,2; B. 0,04 to 0,074: at the constriction 0, 025 to 0,o6 mm. Central nodule large. LunulcC 

 narrow. Costse 3 to 3,5 in 0, 01 mm. alternatiug with double rows of large puncta, about 8 in 0, 01 

 mm. Ocelli usually indistinct. — Nav. gloriosa Brun D. esp. n. p. 34 Pl. XV f. 8. 



Marine: Mexillones Bolivia! Hakodadi, .Japan (Deby Coll.)! 



This is the stoutest and most beautiful of all the forms of D. Crahro. The outline varies. 

 Some specimens are deeply and abruptly constricted, others scarcely constricted. Tlie ocelli are 

 usually not distinct, but in some specimens easily seen. The breadth of the luiiulcE is also variable. 



Var.? susp)ecta A. S. (187.5). — V. strongly constricted, with elliptical segments. L. 0,04 6 

 to 0,092; B. 0,012 to 0,03; at the constriction 0,oo6 to O.on: mm. CostcE 5 in 0,oi mm. Ocelli 

 not distinct. — Nav. su.specta A. S. Atl. XI f. 12, 13, 26, 27. Nav. gloriosa var. infläta Brun D. 

 esp. n. p. 34 Pl. XV f. 12. 



Marine: Manilla (Deby CoU.)! Singapore (Van Heurck Coll.)! Java! .Japan (Atl.), Galapagos 

 Islands! Mexillones, Bolivia (Brun Coll.)! Campeachy Bay (Atl.). 



I have placed this form among the varieties of D. Crahro, only with hesitation, as I never 

 observed on it the marginal row of ocelli, by which the other forms are cbaracterized. 



