1921] NATURAL SCIENCES OF PHILADELPHIA. 345 



FASCIOLARIIDAE. 



Leucozonia rhomboidea (Gabb) Plate XXVI, fig. 9. 



Lugina rhoinbuidea Gabb, Tr. Am. Philos. Soc. xv, 1873, p. 218. 



The first whorl is globose with a depressed tip; 1^ smooth whorls 

 form the embryonic shell. The following whorl has axial folds and 

 spiral threads, the folds weakening and finally disappearing on the 

 succeeding whorls, but persisting as low, rounded peripheral nodes 

 on part of the last whorl. The narrow furrow encircling the base 

 has raised edges in the latter part. Outer lip is lirate within. 

 There are three small columellar plaits. 



Length 13.6, diam. 8 mm.; 6| whorls. 



It is probably ancestral to the recent L. cingulifera. 



Type and a smaller specimen are no. 2947 A. N. S. P. 



Latirus infundibulum (fimel.) 



Gabb, Tr. Amer. Philos. Soc. xv, p. 27. 



Four specimens. The secondary spirals are a little more de 

 veloped than in recent shells. 



Latirus brevicaudatus santodomingensis n. subsp. Plate XXV, flg. 4. 



Differs from recent L. brevicaudatus by the smaller, more nu- 

 merous primary spiral cords. On the convexity of the later whorls 

 secondary spiral threads occupy the intervals, and on the last part 

 of the last whorl there are some threads of the third order. 



Length 57, diam. 24.5 mm. 



Type is no. 2952 A. N. S. P. 



Latirus fusiformis Gabb. Plate XXVI, figs. 2, 3. 



Latirus f us if or mis Gabb, Tr. Amer. Philos. Soc, xv. p. 217. 



Smaller and more slender than L. infuhdibulum, with narrower 

 and more numerous axial folds, rather abruptly terminated above, 

 nine on the last whorl. The spiral cords are also smaller. There 

 are some rather Avidely spaced, unequally grouped and irregular 

 axial lamellae below the suture. 



Length 31.5, diam. 12 mm. 



Type no. 2954 A. N. S. P. 



Latirus elongatus Gabb. Plate XXVI, fig. 4. 

 Tr. Amer. Philos. Soc. xv, 1873, p. 217. 



This species is distinguished by its unually long anterior canal. 



The penult whorl has ten, last whorl nine axial folds. Spiral cords 



are small above, larger and more spaced on the canal. Only the 



last two whorls of the type are preserved. As broken the specimen 



measures : 



