1920.] NATURAL SCIET^CES OF PHILADELPHIA. 321 



Length 24.5, diameter 12 nun. 



Length 31, diameter 16 mm. 



Honolulu Harbor, from the dredger dump on the Harbor side of 

 Sand Island, J. M. Ostergaard. Also from the Kailua coast, on the 

 north side of Oahu, W. A. Bryan. 



This species is less distorted than S. gibherulus L., with a lirate 

 columellar callus, and no excavation of the outer lip posteriorly. 

 S. hulbulus Sowb. is more closely related, but it has a smooth, thinner 

 and less extended columellar callus, and smooth, convex whorls 

 of the spire. 



While the specimens have the appearance of fossils, it is likely 

 that the species is still to be found living. The single one before me 

 from Kailua is 21.3 mm. long, and has the short spiral threads over 

 the swelling behind the lip more distinct. 



In the largest specimen there seems to be but one nodulose inter- 

 mediate whorl of the spire, the whorls having the usual impressed 

 spiral hne below the suture; but as the spire is quite short, the 

 nodules may be concealed by the enveloping whorls. The sculpture 

 of the spire described above is therefore not a constant feature. 



This. stromb was first found by Mr. Ostergaard in 1905. Sub- 

 sequently he found three more. 



Rissoina striatula hawaiensis n. ^ubsp. 



Differ from R. striatula Pease^" by the constantly smaller size. 



Length 4.5 mm. 



Length 5.2, diameter .2 mm.; 9 whorls (type). 



Length 6.4, diametei- 2.7 mm. 



Oahu: Pamiialu, type loc; Waimea. Kauai: Haena. All col- 

 lected by W. A. and E. J. Bryan. 



R. striatula was described from the Paumotu group. Two speci- 

 mens measure: 



Length 8.3, diameter 3.5 muL 



Length 8.6, diameter 3.4 mm. (Cotype, figured in A. J. G.) 



xin. Pelecypods. 



Modiolus matris n. sp. PI. Xll, fig. 18. 



The shell is small oblong wedge-shaped, strongly inflated, thin, 

 bright colored, the prevalent colors being old rose, apricot buff, 

 picric yeUow, or white with vinaceous rays; having a thin yellowish 



"Amer. Journ. Conch. Ill, 1867, p. 296, pi. 24, fig. 31. 



