140 



or with tubeirlet^ or 8[)iiies. Liviii«!,- 

 si)efies (marine) comiiioiily adlieriiio- to 

 alo;v. 



SriUOKHIS AXGULATU8. Htvll. ( Fi^'- 

 80.) (inth Rep't N. Y. State Miis. Nat. 

 Hist., p. <S4.) 



Distinnnisliin^ Characters. — Two or 

 more volutions, outer one robust ; suh- 

 ano-ular sides: ui)per an^'ulai- surface 

 sometimes nodose: a|)erture round or fig. 3o. spirorins anguia- 



. -, , 1 j_i '"■''■• Attached to a shell of 



oval, usuallv nearlv rectaniiular to the Afin/ns spinferoides. Nat- 

 ural size and enlarged. 



plane of volution. lOiiKinai.) 



Found in the Demissa hed. and occasionally in the shales 

 l)ek)w, atSections.") to8, and on tlic Lake Shore (rather rare). 



Genus AFTODETUS. LixusTRciM. 



(18S4: On tlu^ Silurian (^asti-njioda and Ptcropoda of Gi)tland, p. 18.).) 



Tube a sinistral (leftdianded ) coil, somewhat resend)ling 

 a gastropod shell. The form is that of a truncated cone, 

 whose exterior is smooth, seldom showing any traces of the 

 internal coil, though covered with a fine nndnh^se and some- 

 times rugose concentric striation. The apical extremity is 

 flattenecl into a broad cicatrix of attachment, which some- 

 times has one-half the width of the body-whorl. Fsually 

 attached to a brachiopod shell. Walls of the tube thick, 

 somewhat cellular in the thickest portions. 



A V TOD E T i; S L I X 1) S T K ( E .M I . 



Clarke. (Fig. 31.) 



(Am. GeoL, Vol. XIJL, p. •^^4:, 

 Figs. 1,:2, a, May, 1804.) 



Distinguishing Characters. — 

 Kapid expansion of shell : cica- 

 trix of attachment less than one- 

 third the diameter of the body- 

 wdiorl. Found in the Hamilton 



shales, at Hanibui'gh, \. \. Fig. si. Autodetus Undstroemi. 



, , I^ateral ami top view, and section, 



((darke. j x a carter Clarkej. 



