KONGL. SV. VET. AKADEMIKNS HANDLrNOAR. HAND 26. N:<) 2. 103 



narrow, with a row of large granules, formed by the continnation of the costffi. Costae 3 to 4 in 

 0,0 1 mm. alternating with double rows of coarse puncta. Luiiulie none or narrow. Ocelli forming 

 a Tiiarginal band, and, besides, a l)and along the furrows or lunnlffi. 



This species, which is intermediate between 1). Crahro and D. vagahunda, differs from D. 

 Crahro in nothing but the double rows of ocelli. The form of the valve is variable, usually 

 elliptical, but in some specimens panduT'iform. The lunula; are indistinct in some forms, narrow in 

 others. It would be admissible to group the forms of this species togetlier with the forms of D. 

 Crahro. The rar. Kinl;criana ami yahqxigeiisls are analogous to the Pandura-series, the ixir. lata 

 to the separabilis-series. 



Var. Galapagensis Cl. — V. not constricted, elliptical. L. 0,i2; B. 0,o.5 mm. Costte 4 in 

 0,0 1 mm. alternating with double rows of coarse puncta. Lnniilcie very narrow. Ocelli forming a 

 marginal and an interior row. — PI. 11 f. Ki. 



Marine: Galapagos Islands! 



Var. lata Cl. — V. elliptical, not con.stricted. L. 0,ii; B. 0,04 8 mm. ('ostse 4 in 0,oi mm. 

 Lunulffi moderately broad. — PI. II f. 14. 



Marine: Galapagos Islands! 



The fig. 12 PI. CLXXIV in A. S. Atl. represents doubtless a .small, but strongly corroded 

 form of B. hiscriata. 



80. D. vagabuiula Brux (1892). — V. panduriform Avith tongue-shaped segments. L. 0, 13 

 to 0,17; B. 0,06; at the constriction 0,o4.'i mm. Central nodule large, quadrate; its horns nearly 

 parallel. Furrows narrow, linear, with a row of large granules. Lunulte very narrow or not di- 

 .stinct. Costte 3 to 4 in 0,oi mm., alternating with double rows of coarse puncta. Ocelli forming 

 a marginal band and several obliijue or curved rows be.sides. • — Nav. vagahunda Brun A. S. Atl. 

 CLXXIV f. 5. Dipt. vag. Icon. n. PI. II f. 13, 15. 



Marine: Tamatave (Kinker Coll.)! Fossil: S:ta Monica, S:n Pedro (Kinker Coll.) Calif.! 

 D. vagahunda is a transitional form from D. hiseriata to D. gemmatula (var. Beyrichiana). 



81. I), prisca A. S. (1875). — V. slightly constricted, with tongue-shaped or cuneate, 

 obtuse segments. L. O.07 to 0,08; B. 0,o29 to 0,o3 mm., at the constriction 0,02 to 0,027 mm. 

 Central nodule quadrate; its horns parallel and approximate. Furrows narrow, linear, with a row 

 of large puncta. Transverse costse 7 to 8 in 0,oi mm. alternating with double rows of puncta, 

 about 16 in O.oi mm. and ocelli, 4 to 5 in 0,oi mm. — Nav. prisca A. S. Atl. PI. XII 

 f %& to 68 (69?). 



Marine; Nottingham (Maryland)! Atlantic City, N. Jers. (Grove Coll.), Richmond, Va! 

 always fossil. 



This species is very nearly akin to D. gemmatula from which it differs by the narrow 

 furrows. The exterior stratum with small alternating puncta is usually preserved in D. prisca, 

 but never found on TJ. gemmatula, which may be a consequence of the state of preservation and 

 preparation. 



82. D. gemmatula Grun. (1875). — V. slightly constricted, with tongue-shaped to broadly 

 cuneate segments. L. 0,07 to 0,15; B. 0,0,3.3 to 0,062; at the constr. 0,o27 to 0,o.'i mm. Central 

 nodule large; its horns almost parallel. Furrows usually broad, and somewhat dilated in the 

 middle, with a row of large puncta. Costai 5 to 7 in 0,oi mm. alternating with rows of more or 

 less numerous, large ocelli. 



Var. hungarica Cl. — V. moderately constricted. L. 0,o8; B. 0,025; at the con.str. 0,oi8 

 mm. Ocelli forming one row along the margin and one along furrows. 

 Marine: Szakal, Hungary, fossil! 

 Akin to Nav. expedita A. S. (Atl. LXIX f. 6) from Moron. 



