ORTMANN I TERTIARY INVERTEBRATES. 155 



Record of specimens : Cape Fairwcather, i cast and 5 fragments of casts. 



Note: I am not quite satisfied that my identifications of the species of 

 Panopea are correct. As to P. ibari and qtiemadensis I think I have 

 recognized them correctly, but the question remains, whether the new 

 species are really different. I have characterized them only by the ex- 

 ternal form, since no other parts are visible, only in a few cases the shell 

 itself being preserved. I did not find any form that corresponds to P. 

 nucleus of v. Ihering. 



Possibly all the Patagonian species described are really nothing but 

 variations of one and the same form. 



Fam. PHOLADID^E Fisch. 



Gen: MARTESIA Leach. 

 86. MARTESIA PATAGONICA (Philippi). 



PI. XXX, Fig. 5. 



1887 Pholas pat. Philippi, Tert. & Quart. Verst. Chiles, p. 171, pi. 42, f. 8. 



1897 Martesia pat. v. Ihering, in: Rev. Mus. Paul., v. 2, p. 266. 



1899 Mart. pat. v. Ihering, in : N. Jahrb. Miner., etc., v. 2, p. 23, pi. 2, f. 6. 



Shell subovate, convex, gaping anteriorly, the anterior end forming a 

 blunt right angle ; the gap is closed by two callous plates. From the beak 

 toward the ventral margin runs an oblique groove ; posterior to this groove 

 only concentric lines of growth, anterior to it sharp ribs, which run paral- 

 lel ,to the (gaping) anterior margin of the shell, and bear sharp, upturned 

 spinules, disposed, toward the anterior end, in distinct radiating lines. 

 These spinules become smaller near the oblique furrow, and finally, close 

 to it, are indicated only by undulations. The ribs of the anterior part of 

 the shell form, with the lines of growth of the posterior, almost a right, 

 or slightly obtuse angle. Anterior dorsal margin reflected. No accessory 

 umbonal plates preserved in our specimens. On the cast, the radial 

 groove forms a distinct impression, and the gaping anterior margin, where 

 it joins the callous plate, forms another impression running from the lower 

 end of the first impression obliquely upward toward the anterior margin. 



Length, 22 mm ; height, 14 mm ; diameter, 7 mm (x 2) ; (Mt. of Ob- 

 servation). 



