416 PROCEEDINGS OF THE ACADEMY OF [PaRT II 



CHAMIDAE. 



Chama chipolana Dall. 



Chama macrophylla Chemn., Gabb, Trans. Amer. Philos. Soc, xv, 1873, p. 



251. 

 Chama chipolana Dall, Trans. Wagn. Inst., iii, p. 1398; Bull. U. S. Nat. Mus, 



90, p. 135, pi. 25, figs. 9, 11. 



One characteristic valve. 



Chama tampaensis Dall. 



Chama tampaensis Dall, Trans. Wagn. Inst., iii, 1903, p. 1398, pi. 54, fig. 6; 

 Bull. 90, U. S. N. M., p. 135, pi. 24, fig. 1. 



One specimen, the valves together, agrees with Tampa examples. 



Chama involuta Guppy. 



Chama involuta Guppy, Geol. Mag. Dec. ii, vol. i, 1874, p. 444, pi. 17, figs. 5a- 

 c. 



Five characteristic valves, like Guppy 's fig. 5c, and agreeing with 

 Bowclen examples. 



This and the two preceding species were labelled Chama macro- 

 phylla in the Gabb collection. They have been compared care- 

 fully with numerous specimens from type localities of the respective 

 species. 



Echinochama yaquensis trachyderma Pils. and Johns. Plate XL VI, figs. 1, 2. 



Echinochama trachyderma P. andJ., Proc. A. N. S. Phila. 1917, p. 197. 

 Echinochama antiquata Dall, Maury, Bull. Amer. Pal. V, pi. 33, fig. 10. 



A smaller form with fewer, less prominent radial ribs has been 

 named Echinochama antiquata var. yaquensis Maury. A few of 

 these are in the Gabb collection. The larger form with more ribs 

 which we named trachyderma should apparently be called C. yaquen- 

 sis trachyderma. 



Type 2786 A. N. S. P. 



LUCINIDAE. 



Phacoides riocanensis Maury. 



Lucina jamaicensis Chemn., Gabb, Trans. Amer. Philos. Soc, xv, p. 251. 

 Three fine specimens (no. 2666), the largest with an altitude of 

 of 84 mm. Very close to P. hillshoroensis (Heilpr.). 



Phacoides perplexus Pils. and Johns. Text-flg. 41. Plate XXXVIIl. flg. .3. 



Phacoides perplexus Pils. & Johns., Proc. A. N. S. Phila. 1917, p. 197. 

 Lucina antillarum Reeve, Gabb, Trans. Amer. Philos. Soc, xv, p. 251. 



This species has fewer radial ribs than P. octinus Dall, and their 

 intervals are quite shallow. The lunule in the left valve is semi- 

 cordiform, being about half as wide as long. 



