21 



tions to the front margin and anterior angles and half of the sides ; in the 

 posterior or upper half with an abrupt slope, becoming concave on each 

 side of the beak. Surface ornamented with fine lamellose ridges distant 

 from eacli other two or three in one line. 



Loigth of specimen lines ; greatest width, at one fourth the length 

 from front margin, about 8 lines. 



The shell appears to be smooth between the lamellose concentric stride, 

 but in more perfect specimens finer striae may exist. The striae become 

 more crowded in the upper part, where they curve round to the beak. 



This beautiful Lingula has somewhat the appearance of Lingula Belli 

 of the Chazy Limestone. That species however usually exhibits three 

 flat slopes, one to the anterior margin and one to each side. 



Dedicated to the discoverer. Rev. J. B. Perky, of Swanton, Vermont. 



Locality and Formation. — Limestone at Highgate Springs, Vermont, 

 apparently of the age of tlie Black River. 



Collector' — Rev. J. B. Perry. 



LiTUiTES Farnswortiii. (N. sp.) 



Fig. 24. ' 



Description. — Tube very slender, forming about three complete Avhorls ; 

 section circular or very nearly so ; siphuncle small close to the shell in 

 the median line on the outer or ventral side ; septa gently arched and 

 numerous ; chamber of habitation deep. 



Li the best-preserved specimens the first two whorls are in contact, and 

 make a coil one inch across. The whorls then commence to separate, 

 and become more and more distant until at the completion of the third 

 the distance is from l^ to 2i inches. Where the whole spire is 4^ inches 

 across, the diameter of the aperture is one inch ; at 3^ inches it is 9 lines. 

 There are usually from 8 to 12 septa in half an inch, but the distance is 

 variable in the same specimen. In the one figured there are 5 ^r6 in half 

 an inch in the latter part of the second and commencement of the third 

 whorl, but farther on towards the outer chamber there are 12 or 15 in the 

 same distance. The siphuncle is about | of a line in diameter, and about 

 the same distance from the shell. The chamber of habitation appears to 

 be three or four inches deep. No part of the free portion is straight, the 

 curve continuing, although becoming gradually less, quite to the aperture. 

 Surface of shell unknown. 



Tliis species differs from all known American species in being more 

 slender, and in having more numerous septa. 



Dedicated to the discoverer. Dr. P. J. Fahnswortii, M.D., Phillipsburgh, 

 Canada East. 



