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



nating with double rows of somewhat coarse puncta (8 to 11 in 0,oi mm.). — Nav. expleta A. S. 

 Atl. LXIX f. 7, 8. 



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



This form differs from var. Pandura by its shorter, less constricted valves. 



Var. Didelta Cl. — V. slightly constricted, with almost triangular segments. L. 0,08 5; 

 B. 0,04; at the constriction 0,028 mm. Oostse 8 in 0,oi mm. — PI. II f. 8. 



Marine: Sumbava (Kinker Coll.)! 



Var. suMliptica Cl. — V. elongated, not at all, or very slightly, constricted. L. 0,i5; 

 B. 0,052. Costse 3 to 4 in 0,oi mm. alternating with double rows of coarse puncta, about 8 in 0,oi 

 mm. — PL n f. 11. 



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

 mm. in Grove Coll.)! Galapagos Islands (perfectly elliptical form. L. 0,o8; B. 0,04 mm. Costrp. 5 

 in 0,0] mm. Ocelli not distinct). 



Var.? Pandurella Cl. — V. strongly constricted with subelliptical segments. L. 0,038 to 

 0,075; B. 0,011 to 0,022; at the constriction 0,oo7 to 0,oi3 mm. Costse 8 to 9 in 0,oi mm. alter- 

 nating with double rows of puncta, about 20 in 0,oi mm. Rows 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 

 costee. 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. Pandura as the var. suspecta to 

 the var. separabilis and the var. Dirhombus to the var. muUicostata. 



B. Forms with moderately vide lunula. 



Var. separabilis A. S. (1875). — V. gently constricted with elliptical segments. L. 0,o8 to 

 0,16; B. 0,033 to 0,05; at the constriction 0,026 to 0,032 mm. Costse 5 to 6 in 0,oi mm. Lunulse 

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

 Nav. separabilis 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 CabaUo (Atl.), Campeachy Bay 

 (Atl.), Trinidad (Grev.). 



This form is intermediate between var. Pandura and var. muUicostata. 



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

 marginal, not bent toward the central nodule. Costse 5 in 0,oi mm. Lunulse narrow. — PL II f 10. 



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



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

 to 0,2; B. 0,04 to 0,074: at the constriction 0,025 to 0,06 mm. Central nodule large. Lunulse 

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

 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. Crabro. The outline varies. 

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

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



Var.? suspecta A. S. (1875). — V. strongly constricted, with elliptical segments. L. 0,o46 

 to 0,092; B. 0,012 to 0,03; at the constriction 0,oo6 to O.oie mm. Costse 5 in 0,oi mm. Ocelli 

 not distinct. — Nav. suspecta A. S. Atl. XI f. 12, 13, 26, 27. Nav. gloriosa var. inflata Brun D. 

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



Marine: Manilla (Deby Coll.)! Singapore (VanHeurck Coll.)! Java! Japan (Atl.), Galapagos 

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



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

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



