93 



Mr. Davidson's figures (Lm: </t) would, however, atrn-e well enough in these resp. rt- with 

 our form, though this does not seem to be the normal condition of the specie-;. The front 

 portion of the .-hell i- not exhibited by any of the specimen- that I have seen, ami it i-. 

 therefore, impossible to decide a.- to whether it was truncated <.r not. Tlie onl-. 

 /. / which has been described by Hall from the Devonian strata of New York, and which 



has any affinity with the present form, is /.. M>i.- /' '. X. }'.. Vol. IV.. p. '. I'l. II.. tL-. 

 It' this be specifically di.-tinet from /,. m , it is possible that our -p. cim<-n- nnv 



belong to it, but I prefer keeping them di.-tinet at present, as they are considerably larger and 

 broader. 



. Rare in the Corniierou- l/nm-.-tone of 1'ort ( olboi 

 112. LlMifl.A MAI D A (Hali 



Shell linguiform, elliptical, tireate.-t width a little more than halt' the length, narrowing 



_ ntly towards either extremity, obtu-ely rounded and produced below, and more aenti-lv con 



.vard- the beaks. Surface V.TV ^'-ntlv convex below, and a little more convex on 



th-- umbo. marked by fine thread-like -true, which are sometimes crowded in t Hall. 



. N. )"., Vol. IV., j, '.'. I'l. [I.,fig. 1- 



I have only a -injle specimen, but that a remarkably w.-ll-piv-cnvd one, of this form. 

 which I identify with some doubt with L. Hall), from the Hamilton -roup. < I in 



-p.cimeti i- from the < '..ruiferous Limestone, and agree:- in all e.-.-cntial characters with I 



[UOted d.-.-eription, though .-lightly .-mailer than the specimen ti_:ur> d by Hall. It i- 

 appaivntly a ventral valve, its leti-th beiij'j- eit:ht line.-, and its ^ivite-t width about four 

 line- and a half. The -urtace exhibits no radiating .-tri;e, but i> coven d with elevated, 

 tl.re. ad like, concentric lines of urowth, about from twelve to fourteen of which < -ceupy the 

 oe ot'one line. 

 Locality and J-'"/-,it<iti<>/<. Comiferous Limestone, ll.-.--rsvill.-. To\vn.-hip of (tneida. 



I'll. 'i. ||,., is ( Hall). 

 Th'- shellfi .,l'thi> -i-nu- are -mail, and very -imilar in appearance to the d.,r-al vai 



-mall -p.-cimeii- .,f i> . The valve- are Bquamifonn or di-eoid, oalcareoos, and a; 



r.-ntly dc-titutc of a f. ramen in either valve. They differ from th.- -enu- Crania in the ; 

 that tin- -hdl i- apparently free and unattached to other bo.li, j, The interior -l.o\v- a .-tr 

 mn-ciilar call,,-itv. |-].\c,-],t in the character- ,,(' the interior. /'//"//-/. y/x appear- to 

 alt. ..r!i >I < oj's genus /'- '/-/' //'///". with which, perliap.-. further ob-erv;iiion . 



unite it. I have found a .-in trie -p.-ci.-- of the gentle in the (.'orniferou- I inn -tone. 



1 I.'!. 1'imi.llnii's I\-ATI - i Hall). 



I'linii.l.. II llj Pal \. }'.. V..1. III. p. 190, I'l ('III. I!.. Pig 7 



.-hell minute. -litrhtly longer than wide, in .-hap.- |>i-einoid. with a miinit.- . 



tiicajcx. Sui ! '..-.- in-ii k.-d \\ith fin . ri;i- of -ro\\th, about twelve of wh, 



:' on.- line. 



I h.v, e - i. jle example of ihi- form, but 1 li.v.e no doubt M t" it- identity u 



1 1 a i 



It a|.|'e.-,r-, al.-o. \er\ doubtful if the /'. //. of Hall, li 



the Hamilton L-roiip can be -p, cili.-alK ,! from /' ( MM 



-pecimeii ha- 'li of a line ami three ,|irut. . width of a . 



and a half. 



i lorn ferou I. - Port Coll 



(';;- BPIH \ li:. 



Sh.-ll 'he \, niral \ a! 



are! i th. . dor-.-d . I ; I or plicated, w 



lie- | lieatioii- -imp!.- .T bifurcatin". :,nd . t which two or more in 



