INSTITUTE OF SCIENCE, PHILADELPHIA. 265 



Strong threads, of which the one nearest the canal is simple, the others more 

 or less nodulous. The canal is long and closed, the anal sinus distinct, but 

 does not close ; the lower lip is very patulous and projecting. The species 

 is closely related to T. mitella Dall, from which it is distinguished by its 

 rounder whorls, larger size when adult, and proportionally wider sutural chan- 

 nel. I owe to Mr. T. H. Aldrich the opportunity of examining Meyer's 

 types of this and other species. 



Triforis decorata C. B. Adams. 

 Cerithium decoratum Adams, Contr. Conch., p. 117, 1850. 



Older Miocene of the Chipola beds, Florida, Burns; living on the north 

 and east shores of the Gulf of Mexico and in the Antilles. 



This is another species which is likely to be found on further search in 

 the Pliocene of Florida. The Chipola specimens differ in nothing from the 

 recent ones. 



Triforis mirabilis Adams. 

 Cerithium mirabile C. B. Adams, Contr. Conch., p. 118, 1850. 



Pliocene of Shell Creek, Florida, Willcox ; living from Cape Lookout, 

 N. Carolina, south to Florida and the Antilles. 



This species has been confounded with T. iiirris-tliomce Orbigny, and 

 perhaps should be assigned rather to the typical section of the genus than to 

 Mastoiiia ; but the distinction is not very weighty. 



Triforis mitella n. s. 

 Plate 21, figure 10. 



Older Miocene of the Chipola beds, Burns. 



Shell very small, acute-conic, with an acute nucleus of about four nearly 

 smooth whorls and nine subsequent whorls ; each of the latter is a little 

 smaller in front of the suture and enlarges forward so that the base of the 

 whorl overhangs slightly the next in front ; suture well marked, usually with 

 a fine line in front of it, especially on the later whorls ; sculpture of three spiral 

 series of subequal, rounded nodules, the size of which, when they are per- 

 ceptibly unequal, enlarges forward, the anterior row being largest and vice 

 versa ; they are so set on the whorl as to form slightly oblique transverse 

 series, which are not connected by any ribbing, while the basal nodule is in 

 advance in each set ; base of the last whorl flatfish or subconic, with one outer 

 strong and one inner feebler, elevated thread ; canal prominent, outer lip pro- 

 duced in front, with a sinus behind ; both canal and sinus seem to remain open. 

 Lon. of shell 3.3; max. diam. ^ mm. 



This tiny species resembles T. distincta and T. modesta, but is smaller, 

 more slender and more straight-sided. The peculiar eave-like manner in 



