NO. 1192. TRENTON FAUNA OF BAFFIN LAND— SCHUCHERT. 167 



Manitoba, it attains a diameter of 8^ inches. It is a characteristic 

 species of the Trenton. 



Collectors. — J. N. Carpender, A. Y. Shaw, and A. H. White. Cat. 

 No. 28183, U.S.N.M. 



MACLURINA CUNEATA (Whitfield). 



Maclurira cuneata Ulrich and Scofield, Geol. Minn., Ill, Pt. 2, 1897, p. 1042, 

 pi. Lxxvi, figs. 1-3; pi. Lxxxii, fig. 46. 



Of this species there are two typical specimens with the character- 

 istic, small umbilical perforation. 



Collector.— J. N. Carpender. Cat. No. 28184, U.S.N.M. 



MACLUREA CRASSA Ulrich and Scofield. 



Maclurea crassa Ulrich and Scofield, Geol. Minn., Ill, Pt. 2, 1897, p. 1040, 

 pi. Lxxv, i]gs. 12-14. 



One example of this species measures nearly 3 inches in diameter, 

 which is larger than the Minnesota specimens, but this is in keeping 

 with the greater size attained by the Maclureas and Maclurinas in the 

 far north. 



Collectors.— J. N. Carpender and A. Y. Shaw. Cat. No. 28182, 

 U.S.N.M. 



Family TROCHONEMATID^ Ulrich. 



TROCHONEMA UMBILICATUM (Hall). 



Trochonema umUIicatum Ulrich and Scofield, Geol. Minn., Ill, Pt. 2, 1897, 

 p. 1047, pi. Lxxvii, figs. 1-3. 



Of this widely distributed Lower Silurian shell, six specimens are 

 present. They preserve most of the shell, and show considerable sur- 

 face detail. 



Collectors. — J. N. Carpender, A. Y. Shaw, and A. H. White. Cat. No. 

 28186, U.S.N.M. Other specimens collected by Mr. li. W. Porter are 

 in the American Museum of Natural History. 



TROCHONEMA (EUNEMA) ROBBINSI Ulrich and Scofield. 



Trochonema (Eunema) robbinsi Ulrich and Scofield, Geol. Minn., Ill, Pt. 2, 

 1897, p. 1053, pi. lxxvi, figs. 11-15. 



Three examples of this species are present, only one of which is well 

 l)reserved. These were seut to Mr. Ulrich for comparison with T. rob- 

 binsi and T. salteri. He writes as follows : 



These specimens possibly indicate a form intermediate between T. (E.) similis and 

 T. {E.) robbinsi Ulrich and Scofield. The upper whorls of the best specimen agree 

 rather closely with the former, while the last whorl, with its relatively narrow 

 peripheral band, is more in accordance with the latter species. It is to be borne in 

 mind, however, that it is only the shell-less portion of the specimen that agree 

 with T. (E,) similis, the opposite side of the same whorls showing no trace of (he 

 ridge near the suture, which is strongly developed and is characteristic of T. similis. 



