123 



Locality and formation. Not uncommon in the Hamilton Formation, Bartlett's Mills, 

 near Arkona, Township of Bosanquet. 



CRUSTACEA. 



The remains of Crustacea are not uncommon in both the Corniferous Limestone and the 

 Hamilton Formation of Western Ontario ; but they are lor the mo-t part ill-pre-. -rved and 

 fragmentary, and I have only been able to identify with certainty the well known species, 



Pro his (Hall), Pli'i'-n/K mini (Green), l>iilinan>'- .< !' ;; iC.reen . and Le- 



perditia (!} i>iiii'-tn!ifiTii (Hall). Besides these, our collection includes fragments of -OUR- five 

 or six additional species of Trilobites, which must be retained for further examination. 



153. PROETTS CRASSIMARGINATUS (Hall). 



Calymene erasamarginatus (Hull), (Jeol. Rep. Fourth Dist. New York, p. 17-. tii_ p . 5. 



J'ft illi/'-ix (1) crasaimarginxtus ; cited by Billings, Cu/i. ./>///<'//, Vol. \'l. p. 362. 



/' <T<i.-iiii'ir<iHint>i- i 'Hall). Fifteenth Report on the State- < 'abiin-t. p. Inn. 



This familiar species is^chicflv known by it,- p\_:idiiim, which is a common fossil in the 

 Corniferous Limestone. The pygidium is somewhat wider than loii._r, very convex, and mar- 

 gined by a thick concentrically-striated border, whence the specific name i.- derived. The 

 axis is strongly convex and prominent, with thirteen or fourteen rings ; and the lateral lobes 

 are also very convex, and exhibit from twelve to thirteen ribs (Fig. f>ti). Almii: with the tail-. 

 occur sometimes exceedingly convex and prominent glabellae and also free cheek-. Loth of 

 which probably belong to this species. 



l.'-'-aiitij nnd Formation. C'oruiferous Limestone, Ridgeway, Port Colborne, Lot 6, Con. 

 1 Wainfleet, and Hagersville. 



154. DALMANITES BOOTHII (Green). 



Crypticms Boothii (Green), Silliman's Am. Jour, of Science, Vol. 3'J. p. ."-14. 



(( ireen). Ibid., p. M I'i. 



Dabn / Hall), Fifteenth 11. -port on the Stat.- Cabinet, p. 91. 



The tail of this pretty little -peci.- .tig. ;"><'>. >. which i- rnimnunly known by the nam- 

 of Dalmanitti catttteh . i- a by no means very ran- I'.'s.-il in tin- Hamilton Formation .il'Oi. 

 rio. Th>' j.y_ r i.liuin i.- -.mieirciilar, with a m.'.l.-rately prominrnt. tapering axi-. \vhidi. wln-n 

 complete, exliibit- from nine to twi'Ue riiiL r -. The lat.-ral loin- an- depressed, and exhibit 

 five or six pleune, the \tremi tic- oli which arc pmlnn-. ! be \-n.l the man: in in the lorn: 

 many obtUSely-poioted jii-nc. --.- n|- cxpniri.'n- which arc L '.-ntlv curve, 1 baokwafdl 



Between the lateral groups of th.-e prooesses, oooopyicg th.- c.-ntri- ..f the py-ji.lium i- a 



wider and -hort.-r pointed prm-,--- extendini: backward- Ir.'in the r.'imded < xtrcmity of the 



axi-. The entire -iirta.-e i- .irnaiinMitcd with minute papiil.-r nr grUtQ 



/.i,,-.//////,; . Hamilton 'jnmp. \\idder, and liartletl'.- Mill-, near Ark.'tia. 

 Town.-hiji of r,..-an.|iiet. 



155, I'll \' OK KAN A (I il< en). 

 C 'T rallO ' I ircen i. Mmin-raph. p. TJ. 



Phaeopi ranO (Il.illi. Fiftrenih |;ep.,rt on the State Cabinet, p. 



This well-known -p. cj, - i- .-hi, tl<, represented by detached idinm 



i- not of v.-rv iincnmmii occurrence, and the bn.|\ ril : -mnall\ -. i-n 'II die 



shield (\ - IP nl\ -. mieirculai . and the |..-teri"r an.'lc- ai. .\ prod 'k 



w.ird- The glftbells ibbmi-, l>m somewhat deprestted OD the npj.er -mi ut 



one-third wider thin long ; the lob. obsoorelj marked onl thi neck-ftirrow narrow but wett- 



ilc|ine<| , and the ii.-ck. - _'iii. nl wide and . . <n -picii"ii- 'II.. .iiiiiit, 



ri-iiiL r n.-.ith a- hi_-h a- iln- tup of tin- -I ib. ll.t. with lar-e leu-.-- Tl 



lon-er than the head, it- .-id.-- ic-arly -trauht. and r 



orne.ari', M Tic im is twii : i -wid-r. i-.-ul.irl\ r. .tind. d b- hind. 



