No. 2.J 



MONTGOMERY — A DEVONIAN BLASTOID. 



81 



Mr. Conrad named the genus Nucleocrinus (L. nucleus kernel 

 of a nut, and Gr. krinon a lily) in 1842 ; Troost gave it the ge- 

 neric name Olivanites in 18-49 ; and in 1852 Dr. Ferd. Roemer 

 called it Elseacriuus. In 1862 Dr. Hall gave the name luciiia 

 to a species gathered from the rocks of the State of New York. 

 To this species, in the absence of specimens of lucina with which 

 to compare it, I provisionally refer what may possibly be a new 

 species of Nucleocrinus. 



The echinoderm in question, found as already stated, in the 

 Hamilton formation, Lambton Co., was associated with numerous 

 corals, chiefly of the genera Cystiphyllum, Diphyphyllum, Erido- 

 phyllum, Heliophyllum, Stenopora, Favosites, Alveolites and 

 Aulopora, with various Brachiopods (Spirifera, Spirigera, Stro- 

 phomena, Strophodonta, Cyrtina, Chonetes, etc.), Gasteropods, 

 and Bryozoa. It must be placed in that division of the Blastoidea 

 possessed of a calcareous, jointed stem and a lateral interambu- 

 lacral aperture. In general appearance it is somewhat barrel- 

 shaped, being thicker a little above the middle than at either ex- 

 tremity, and considerably flattened at the summit and base. Its 

 greatest length is about 4J- lines ; and its greatest transverse 

 diameter about 3f lines. 



Fig. 1. 



Fig. 1. Nucleocrinus lucina (?). From the Hamilton shales, Ontario^ 

 Canada, a. View of base, twice the natural size, shewing point 

 of attachment of stem, and the five radials hearing each a long, 

 central elevation terminating in a concave projection orer the 

 end of the pseudambiilacrum. h. Lateral view, one and three- 

 fourths the natural size, shewing the anal orifice, and anal plate 

 with its two adjacent inter-radial s. c View of upper surface, 

 twice the natural size, shewing plates in the oral region, the 

 lateral anal orifice, and the pore-plates of pseudambulacral areas. 



Fig. 



a. b. c. 



Fig. 2. Pentremites Godoni. From Lower Carboniferous rocks of 

 Illinois, U. S. Natural size. a. View of base, shewing three 

 large basals, and attachment of stem. b. Lateral view, shewing 

 broad, petaloid, pseudambulacral areas, with large transverse 

 striae, very visible to naked eye. c. View of superior surface. 



Vol. X. 



No. 2. 



