202 



PALAEONTOLOGY OF NEW-YOEK. 



faces are near the outer edge, not quite reaching to it nor extending to the centre ; 

 canal round. The several joints attached to the specimen fig. 2 b, except in the form 

 of the canal, have the same character with this fragment, vi^hich is referred to that 

 species. 

 Fig. 2 Z, 7n. The end view of this fragment, and the same enlarged, showing form of canal and 

 crenulations of the surface. 



Position and locality. This species has been found in the shale at Lockport and vicinity. 

 Perfect specimens are extremely rare*. {Collection of Col. Jewett.) 



^*^ The fragments of crinoidal columns figured on Plate 44, will be noticed at the end of the 

 article on Crinoidea. 



592. 3. LECANOCRINUS SIMPLEX (-n. sp.). 



Pl. XL VI. Fig. 2a-e. 



Body ovoid, the smaller extremity at the base ; calyx composed of three minute anchylosed 

 plates ; pelvic plates elongated, three of them hexagonal and two pentagonal ; four of the 

 scapular plates equal, the fifth divided, resting lower down upon the costals, and producing 

 an alternation in the joining at the lateral margins ; arms dividing on the second joint above 

 the scapular plate, no farther subdivisions being observable ; no intercostal or interscapular 

 plates apparent ; surface marked with minute ornament ; column small, the joint attached 

 showing a faint pentagonal impression. 



I have referred this species to the Genus Lecanocrinus, from its general similarity to the 

 other species, except in the intercalated plates, which are not visible. The only irregularity 

 noticed is that in one of the divisions the costal plate is smaller, and is succeeded by two 

 scapular plates, producing an alternation in the lateral union of the plates. The form of the 

 calyx plates, the scapular and arm-joints, and the subdivisions of the arms, are all similar to 

 the type first appearing in Ichthyocrinus. The specimen figured is probably a young indi- 

 vidual, and it is not impossible but in its more advanced stages it may present the detailed 

 characters of the genus in the interstitial plates. 



Fig. 2 a, b. The specimen, natural size and enlarged. 



Fig. 2 c. The crown, showing the ten subdivisions of the arms closely infolded. 



Fig. 2 d. An enlargement showing the ornamented surface of the plates. 



Fig. 2 e. The structure of the cup, carried to the third plate beyond the divisions of the arms. 



The minute joint of the column attached to the base of the specimen is too obscure 

 to afford any positive evidence in the identification of the species. 



Position and locality. In the shale at Lockport. 



* An imperfect specimen was figured in the Geol. Feport of the Third District, 1 843, under name of Cyatho- 

 CRiNUs, which was the only individual I had then seen. The two perfect specimens now figured have been obtained 

 by Col. Jewett. 



