dall: mollusca and brachiopoda. 357 



Mopaliidae. 



PL.ACIPHORELL.A Carpenter. 



Placiphorella blainvillei Brodehip. 



Chiton blainvillei Broderip, P. Z. S. Lond., 1832, p. 27 ; Reeve, Conch. Icon., Mon. 



Chiton, pi. 3, fig. 13. 

 Mopalia blainvillei Gray, P. Z. S. Lend., 1847, p. 69. 

 Placiphorella blainvillei Dall, Proc. U. S. Nat. Mus., 1886, 9, pp. 210, 211 ; Piisbry, 



in Tryon, Man., 1892, 14, p. 310, pi. 66, figs. 26-32. 



U. S. S. " Albatross," station 3368, near Cocos Island, Gulf of Panama, in 66 

 fathoms, rocky bottom; U. S. N. Mus. 122,968. Original locality of the species 

 Lobos de Tierra Island, Peru, on a stone from seventeen fathoms (Cuming). 



SCAPHOPODA. 



SOLENOCONCHIA. 



Dentaliidae. 



Dentalium megathyris Dall. 



Plate 19, figure 1. 



Dentalium megathyris Dall, Proc. U. S. Nat. Mus., 1889, 12, p. 293, pi. 9, flg. 1 ; 

 Stearns, op. cit., 1893, 16, p. 424 ; Piisbry, Mon. Scaphopoda, Man. Conch., 

 1897, 17, p. 67, pi. 15, figs. 29, 30, 31. 



The following table shows the distribution of this species as far as known : 



Station. Locality. Depth. Bottom. Bottom temp. F. Mus. Reg. 



♦3360 Gulf of Panama 1672 sand 36°.4 122,982 



*3361 " " 1471 ooze 36°.6 122,977 



*3381 " " 1772 mud 35°.8 122,975 



3399 " " 1740 ooze 36°.0 122,980 



3407 ofE Galapagos Ids. 885 " 37o.2 122.978 



3413 " " 1360 " 36°.0 122,979 



3431 Gulf of California 995 mud Zl<=>.0 122,976 



3432 " " 1421 " 37°.8 122,981 



3414 off Tehuantcpec 2232 " 38°.6 122.974 



2788 ofEChiloeld. 1050 36°.9 110,665 



2789 off S. W. Chile 1342 86°.9 87,658 

 2807 off Galapagos Ids. 812 ooze 88°.4 117,830 



As in previous instances the specimens in nearly all cases were badly eroded. 

 A considerable range of variation was observed in the matter of curvature, some 

 being straighter than others taken in the same haul of the dredge, some thiuuer- 

 shelled, in many individuals the aperture being almost absolutely circular. 



