I'TICA SLATE AND HUDSON-RIVER GROUP. 273 



329. 10. CRAPTOLITIIUS SEXTANS (n. .'fp.). 



Pi.. LX.XIV. Figs. 3 a - e. 



Slender, bifuicating from the base; branches linear, straii^ht, serrated upon the outside; 

 serratures oblique ; teeth sharp, and extended into a slender iiuicronate point. In perfect 

 specimens, two small seta; extend from the base, one on each side. 



This small species appears to i)e (piite distinct from either of the others. In a considerable 

 number of specimens examined, it, bifurcates at the base, from l)eneatli which two slender 

 spines or bristles proceed. The bifurcations are straight, ami regularly diverging at an 

 angle of sixty degrees. The angular teeth on the outer margin always preserve a mucronate 

 point when perfect, and this character is sufficient for identifying small fragments. 



Fig. 3 a. A fragrncnt of slate on whicii are two specimpos of this species, with straight diverging 



branches. 

 Fig. 3 i. A portion of one of these magnified, showing the mucronate teeth. 

 Fig. 3 c. Specimen with larger branches. 



Fig. 3 d, d. Two specimens, showmg the appendages at the base. 

 Fig. 3 e. One of the last magnified. 



Position and locality. This species is known to me only in the black slates of the Norman's 

 kill, near Albany. {State Colltciwn.) 



3.30. 11. GRAPTOLITHUS FURCATUS (/(..?;).). 



Pl. LXXIV. Figs. -1 a -/. 



Stipes slender, bifurcating near the base; branches diverging, curved in the centre, and 

 converging towards the extremities ; stipe below the bifurcation serrated on both sides, 

 branches serrated on the outside ; teeth nearly as wide as the branches, rectangular, obtuse ; 

 inner side of the branches more obliqely serrated. 



This small and peculiar species is readily distinguished from cither of the preceding, by 

 its curving bifurcations, and shape of the serratures. In a laige number of specimens 

 examined, it preserves the form and character given in tiie figures, and a single branch 

 can be distinguished by a careful comparison. It differs in its mode of l)ifurcating from G. 

 ratnosus, and is always smaller and narrower. 



Fig. 4 a. An individual on the same stone with 3 d, showing the difference in form. 



Fig. 4 i. A magnified portion of the same. 



Fig. 4 c. A small specimen, with the branches more converging than usual. 



Fig. 4 d. A portion of the last magnified, showing no serratures on the inside of the branches. 



Fig. 4 e. Another specimen, similar in form to 4 c. 



Fig. 4/ A part of the same magnified, showing serratures on the inside of the branches. 



Position and locality. In the glazed slates of the Normairs kill, near Albany, 

 [ Palaeontology | 35 



.t ••' 



