

.InllAN K1.I.1J. 



[SEC. ARCT. EXP. KB AM 



In the case of />. <'<in<lrnxix the ineasureinents are partly deter- 

 mined from examples from Scaumenac Bay. partly from TKAOLAIR'S 

 leo.n-lrnctioii. and in Hit 1 ca-e of B. lii/drojiliila from TRAO.UAIB'- ' 

 excellent illustrations and reconstruction. 



Length of unt. 

 i.l' ventr. later, 



proximal part plate from post. 

 of arm. marg. to inner 



cross rib. 



Propi.rtn.il 

 Figure. 



1. Form from ( jalgeoildeii, Klles- 

 mere Land ........ 



"2. B. ciuitii/i J/N/.S -Win i. Specimen 

 tn.m Scamneiiar Bay .... 



3. B-canadensisWttn. T 

 reconstruction 



Ill mm. 



42 



4. B. liiiili-tifiliiltt Ai.. THAUI MK'- 

 reei.nstriicHon . 



17-18 



33 mm. 



58 



.",1 



31-32 



1: 1.71 



1 : 1..% 



1 : 1.-21 



1 : 1.8 

 1 : 1.77 



A- will he seen, the form described differs very considerably from 

 I: r<ui<idensis WHIT, hut agrees almost entirely with B. liiidruphila Ac. 

 which i> known in excellent specimens from Dura Den in Fifeshire, 

 Si-nlland in the Upper Old lied Sandstone. 



Since a!-o according to 'PuAguAiR's description the sculpture, the 

 >horl and hroad form of the anterior hotly plates, and the size on tin' 

 \\hole agree in the two forms, I may presume that the remains from 

 Klle-iiM-n- Land are either identical or nearly related to 11. l///<l>-<>/>l/ilu 

 Ac. I ha\e not heen ahle to discover any American form showing clo-ei 

 agreement. The mo>l nearly related appears to he B. C(in(t<li'nxix \VniT 

 \vhich. h;i\\c\ -er. has considerably -liorler ai'ins. 



It i> difficult to deteniiine exactly whether the fragments with coar>er 

 -i-iilpliire aUo helong In /;. hi/dro/ilii/a A,. The variations of sculpture 

 and diiiii-n^i.His in the case of I>. cfnuult'Hfiis WHIT, show that the-.- 

 fra-iiii-iil> ma\ |io>-,ihly helong to the same form as the others. One 

 Iramiienl. ho\\e\er. >how> ^o cnar.-e and so markedly nod(se nhs. that 

 it can scarcely helong to the >nnie specie-. 



Mori/, on. I'Vom the dark >i-ln-l- of Galgeodden, with remains of 

 plant-. and from the fi.-h hori/oii of Skrap X'alley. 



II. II I i: .,,. MI,. The A-l.-n,lr|n,lcr. M..iior. I'al. Soc. l.s'H ami t'.K)4. 



