J0NE8.] PAL/KOZOIO OSTRACODA. *73 



tho posterior, nor (MlJjor of the oUu;r lobos is siilcatod. A broad, 

 flattonod area is distinct all round within the mai'<^in. There are two 

 sixM'imons lilce that lin-iirod in tlie Q. .1. G. S., ISDO, ])1. ii, fig. 6, but 

 dilVoring slightly from it in the proportions of the lobes. 1 have not 

 yet met with a specimen having a lobe quite divided into two ])arts, as 

 in (he wMxxlcut, fig. 1^0, published in 18G(). Tho fig. (I just referred to 

 has th(^ third lobe Hlighlly modified by a faint ()bli(j[ue sulcus, but it is 

 not actually divided. It was kindly submitted for examination by Prof. 

 R. P. Wliitfield, of New York, and is labelled '' B. equilatera:' Tt is 

 not, howevei', like (he figure ])ublished in the "Canadian Naturalist 

 and (Geologist," ISfJO, which seems to have a strong curved ridge, a 

 small central lobe, and two liKle lobes (not mentioned in the descrip- 

 tion) re])resenting a (bird I'idge. Indeed, the little woodcut (1860) 

 her(^ referred to has a relatively large, curved posterior lobe, a small 

 isolaled mid-lobe high up towards the back, and two separate small 

 lobes an(eri()rly. Were it not that we have some named specimens 

 from Ai'isaig and a special description at j). PJ8, " Oanad. Nat. Geol.," 

 ]8()0 (copied in " Acad. Geology," 1808 and 18Y8), we might think that 

 this obscui'c little figure was intended foi- some such small form of 

 B. tiiberculata as the one shown in oui- lig. 1, pi. xi. 



Br. lIoneymMii mentioned this species in the Quart. Journ. Geol. Soc, 

 vol. XX, 18(U, p. 344, as occurring in his grou)) Dof the Arisaig strata. 

 M^he original of ])1. xi, fig. (), is fi'om Stonehouso Brook, Arisaig, Nova 

 Scotiji, in (he litncslone conlnining Prlmitia mundala, P. ovataf, and 

 B eyrie hi a tuOercula fa. 



We have here :i radier dilUcult point to consider. Is the description 

 <jv iUofigure given both by Prof. .lames Hall, in 18G0, and repeated by 

 Pi'incipal (now Sir W.) Dawson afterwards, to guide us as to the species 

 with which tb.ese s])ecimens are to be collocated ? I think that really 

 thei'e is no doubt that iho fiijiire is that of a small Beijrichia tuherculata, 

 or one of its varieties, and that the description is that of such a Beyriehia 

 as has been sent labelled and named as B. (rquilafera, and is figured in 

 the Quart, .lourn. (ieol. Soe.. ISDO, pi. i, fig. (>, and in pi. xi, fig. G of the 

 present paper; the only difierence being tha( the middle lobe in the 

 desi'ription is i^uite isolated, whereas in the figures here referred to — in 

 the former it obscurely joins the ventral curvature of the front and hind 

 lobes — and in the latter it (juite unites therewith, bringing this form 

 very near (o />. Kla'deni. These three stages of dilVerence may well be 

 due (o varying states of preservation in the specimens, as they are all 

 casts. 



The two separate lobules at one end of tig. 20, p. 158 (1800, and fig. 

 217, 18()8 and lS7S)do not belong to the description at all, but they 



