lExtractiid from the GroLoaiOAL Magazine, Vol. V. 



February, 18G8.] 



No. 2. 



I 



DESCRIPTION OF TWO NEW SJ^ECreS OF STIIIOK- 



LANDINIA. 



By E. Billings, P.G.S., Paln^ontologiijt to the Geological Survey of Cunada. 



(I'LATE IV.) 



N 'ho "OanaJian Naturalist and Geologist," vol. iv p. 134, 

 fif^^s. 8 (1^.59), I t],^au't'l1 -'i small specimen ut' ii ?>|)eciefl of 

 StrirhliuuJinia under the nonie ot .S. Jens, but, at the samo; time., 

 Ktat^'d Ihat .1 \va.s wot certain whether it was the true S. lots or a 

 varietJ^ It was more pointed in front than any of tlie English 

 specimens f had seea. Jt I'ad Ijoen colleeted in the Middle Silurian 

 rwcks on tin; Island of Antieosti. along with nume'ruui (jiher spcei- 

 mens. most of tliem in a fragnnmtary condition. Aiiiong" thesn I 

 thought th;it S. Urnta could also be identilied ; ajid thus lioth of the 

 Britisli species hoA'e been cited in stiveral of the pui.)[ioaiions of our 

 Survey. 



Thnjugh tlio kindtiess of the author I received, sev<Tal monthm' 

 ago, "I'art 2" of Mr. Davids(Mi'.s "IMonograpli of the lirilish 

 Siluiian Brachicipoda." The clear descriptions arid lieautiful illus- 

 trations of this magniticent work at once enabled me to perceive 

 tliat we have nut (so fir as is yet know)i'i either of the two s]»ecieH 

 above mentioned. What I supposed to bo jS'. liraia, is the adtdt of 

 the form iigured by me as S. lens. The young and small individuals 

 ar',' smooth ; but with increasing size and age they be?ome more and 

 more strongly riblxMl. 



While re-examiuing the whole collection, with a view to this 

 paper, I broke up several pieces of limestone, whif^h were almost 

 entirely ri)mposed of the iniperf(-ct and detached v.tlves of another 

 S['Ocies, and succeeded in getting out several specimetis, sidTiciently 

 perfect to authorize a description. We have thus two new species ; 

 and, as the errm- with regard to .S'. Jirota and S. h;m has Yyevn 

 transferi'ed from my publications into He\eral imjtortant English 

 works, it is thought advisable to describe them in the OEiix.ooiOAjj 

 Magazink at once, wdthout waiting for my next report, which cannot 

 be issued for several months. 



StricHandiitia DavidHonii, sp. n. — Plate IV. Figs. 1 -lof. 



Spue, Char. — Shtll longitu'liiially ovnte ; sicips anil nanlinal extrotnity rounded; 

 front ufsii.illy with a liiijfuit'orni extcnsidii about one-third of tlie whoif width, and of 

 variablfi length, sometimes simply narrowed from the mid-Ungth to a roiiiuted point; 

 greatest width about the middle, or a little above. The valves are almost equally 

 convex. The ventral vaWe has, in young indiyiduals, an obscure mesial sinus, which 



