102 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 78 



"LEPERDITIA" TATEI Chapman 



Plate 10, Figures 14r-16 



Leperdiiia tatei Chapman, Proc. Roy. Soc. Victoria, vol. 31, new ser., pt. 1, 191S, 

 p. 109, pi. 9, figs. 1-3. 



A reexamination of the type specimens is necessary before the 

 affinities of this species can be determined. Possibly more than one 

 species is represented among the specimens figured. 



Occurrence. — Upper Cambrian, Archeocyathina limestone: Ciirra- 

 miilka, South AustraHa. 



"LEPERDITIA" cfr. SOOTARIA Barrande 



tLeperdita solilaria Barrande Suppl. Sil. Syst., p. 532, pis. 23, 24 (Etage E). 

 Leperdiiia cfr. solilaria Burr, Amer. Geol., vol. 25, 1900, p. 47. — Grabau, Boston 

 Soc. Nat. Hist., Occ. Paper 4, pt. 3, 1900, p. 661. 



The above references are inserted to indicate the occurrence of a 

 member of the Conchostraca in Massachusetts, although no illustra- 

 tions of it have been published. 



Occurrence. — Cambrian, North Attleboro, Mass. 



"LEPERDITIA" VEX ATA Hicks 



Leperdiiia? vexata Hicks, Quart. Journ. Geol. Soc. London, vol. 27, 1872, p. 396. 

 Larval trilobite? Jones, Quart. Journ. Geol. Soc. London, vol. 28, 1873, p. 184, 

 pi. 5, figs. 17, 18. 



The doubt as to the position of this form is indicated in the 

 synonymy. 



Occurrence. — Middle Cambrian (Menevian): St. Davids, Wales. 



"ISOCHILINA" SWEETI Chapman 



Plate 10, Figure 18 



Isochilina sweeti Chapman, Proc. Roy. Soc. Victoria, vol. 31, new ser., pt. 1, 1918, 

 p. Ill, pi. 9, fig. 5. 



The generic aflfinities of this species, like the preceding, can not be 

 determined without a study of actual specimens. 



Occurrence. — Upper Cambrian, Archeocyathina limestone: Curra- 

 mulka. South Austraha. 



MODIOLOPSIS THECOIDES Matthew 



Plate 1, Figure 34 



Modiolopsis thecoides Matthew, Bull. Nat. Hist. Soc, New Brunswick, vol. 4, pt. 

 3, No. 18, 1899, p. 191, pi. 1, figs. 7a-c; Trans. Roy. Soc. Canada, ser. 2. 

 vol. 5, sec. 4, 1899, p. 103, pi. 5, figs. 7a-c. 



Only the right valve is known ; it is remarkable for its long, narrow 

 shape and earlike anterior end. When this is concealed the shell is 

 easily mistaken for a Hyolithes, the form of the posterior end and the 



