NO. 2225. NUCULITES FROM THE MAINE SILURIAN— WILLIAMS. 39 

 NUCUUTES ABNORMIS, new species. 



Plate 11, fig. 16. 



Shell rhomboid-ovate, flattened, resembling in outline a Devonian 

 Gypricardella, but with the clavicle and crenulate teeth of Nuculites. 



The antero-posterior diameter is 28 mm. and height (estimated) 

 20, or at least 70 per cent of length. Beak situated about one-third 

 of length back of front margin. The umbonal ridge, as in Gypricar- 

 della, with central body of the shell depressed convex, the postum- 

 bonal slope is concave and falls off abruptly from the umbonal ridge. 

 The hinge behind the beak is marked with the characteristic crenu- 

 late teeth of Nuculites and the clavicle is distinct and slants forward. 



This specimen was found in the same shales with Nuculites spedo- 

 sus, from which it differs very greatly in form; nevertheless it is quite 

 possible that the difference in form is due to metamorphic distortion 

 after fossilization. 



Formation and locality. — Pembroke formation, gray shales on west 

 side of Coffin Neck, opposite Gooseberry Island, Lubec (loc. No. 

 5.44.2 A). Tliese shales lie immediately above some light greenish 

 shales containing an Edmunds fauna. 



Type-spedmen.—CsLt. No. 62881, U.S.N.M. 



NUCUUTES CHRYSIPPUS, new species. 



Plate 12, fig. 5. 



The name Nuculites chrysippus is given to an elongate, cuneate 

 form similar to that of N. cuneiformis Conrad. Most of the terms 

 used in describing that species apply equally well to this one. 



Shell of medium size, elongate-ovate, cuneiform, widest in front 

 and pointed behind; length (22 mm.) twice the height (11 mm.), thus 

 differing from N. cuneiformis, the length of which is greater than 

 the height. Basal margin gently curving in the anterior part, becom- 

 ing nearly straight behind. Posterior extremity narrow, but less so 

 and less elongate than in N. cuneiformis and obliquely truncate 

 behind. This truncation of the margin hes between the two faintly 

 expressed umbonal ridges which radiate from the beaks. At the base, 

 they are 3^ mm. apart, the space between them is flat and marked by 

 two intermediate faint corrugations as in N. corrugatus. The cardi- 

 nal line is nearly straight. Anterior end sloping rapidly in a straight 

 line from the beaks and abruptly rounded below. The beak is at 

 the extreme front (if the axis of the shell be made parallel to the 

 hinge fine). If the margin of the base be made the transverse axis 

 of the shell, the beak stands near the front, which is broadly rounded 

 to the center of the base and the shell is very oblique and the umbonal 

 slope is greatly elongate and bounded by two faint diverging ridges. 

 In front of the more anterior of these ridges, there is a broad shallow 



