- 
246 Proceedings of the American Association. 
which are usually regarded as identical, but which are entirely 
distinct. 
Mr. H. said he did not intend to go into detail in this place, 
with remarks of this kind, it being his intention merely to pre- 
sent the results of his investigations in the strata constituting the 
lower term of the system; these had been arranged in tabular 
form, showing the number of genera and species of each class or 
order, with their distribution, and range beyond the point of their 
first appearance. In this table nothing had been supposed, every 
thing presented having been verified from observations, and the 
slightest evidence, such as the occurrence of the fragment of a 
fossil in a higher position, had been seized upon to show the 
greater range of the species. 
Tuble showing the number of species peculiar to each Rock and Group, and also 
the number common to several groups. 
£ 
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Elo 25/2 |2 118) 
El bem he sitisiz 
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CLASS OR ORDER. o\ei¢ 242.18 le | Sloe ke elo! ede 
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<} a ie Lie j=} 2 ef 2@/Sj/z |2e\a Sales ot 
BF Els} S| Ey ela le Beis ls i138) eB le} 
ca Te pee ee 2a cis l= c/o 21" 0s « - 
ale = 12 lal eb si€lEltslvisifiel e IS. 
S R A >|o <4 a|& Ee PO ea ol oo) Ss bi 
BeiSislolelsiSi3 isis 42's lsicisils Is 
Swizlzls lf |SiBPS Sis leeS isle le) 2 is 
y= Wa ok a -or4 ~-\- Si jee le oe 
JE OO | Me joie Pe OO ae ie ee ie 
Plante, ee ee es) ah Wane ied hee nal OS 
sat fff] ofa lad kel] = beb-f-feoa 
Zoophyta, a! eed a) ee ee Oe a ee 
Crinvidea, : =| Es Oia Ooo br | imag eg Gc 2 SaSa D ied ee 58 
ere rr 7| 712) 110) «| +] 51) +! 3/1 (Stl? - 
ephala, 12) 498-1 +) 0) TF] +} Q6 alts ae -| » 14th? 2? 
\Gasteropoda, 17 71h +) 813} Ot -| 8} - | 6 “tq 1 | +}: i4the 
Cephalopoda, 11) 68} -| 1 4] £{10| 40/2) 5] - 2] - rend 4B) 2: © 
Crustacea, . 14) 888 -) aie baal ag -| > Ae app eee Te 
Total, 95331] 3 13451613188 S54 OT |1 | 1 | 13 6/2! 20 3 
The proportion of species in the different orders of Mollusca, 
with the exception of Acephala, is nearly the same. otwith- 
eg ae 
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3 ‘u ther Orders ne } ‘ k ad N " the s a 
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