BRYOZOA. 

 Reduced analyses of Bryozoa — Continued. 



35 



SiOj 0.38 



(Al.Fe)203 41 



MgCOj 2. 80 



CaCOj 94. 90 



CajPoOs Trace. 



1.45 



8 



}., 



Ca^dj. 



100.00 



59 



,59 



95. 2.S 



Trace. 



1.54 



loomo 



' 1.42 



. .72 



. 17 



94. 8(i 



Trace. 



2.83 



10 



9.57 

 90.43 



(?) 

 (?) 



11 



12 



1.15 

 .50 



8. 9(i 



86. 89 



.43 



2.07 



16.71 



2. 25 



10.19 



64. 51 



1.58 



4.76 



13 



12.94 



1.54 



11.08 



63.29 



2.68 



8.47 



100. 00 I 100. 00 I loa no . inn nn inn nn 



Reduced analysis No. 10, of Amatlda, requires explanation. This bryozoan was one of the 

 mossy or fernhke forms and contained inclusions of sand and minute shells. Its organic matter 

 was very large, and the entire material available was insuflicient for a good analysis. The 

 figures given for it in this table merely represent the lime and magnesia alone, calculated as 

 carbonates and to 100 per cent. The analysis is obviously of small significance, except in so far 

 as it gives the ratio between magnesia and lime. To that extent it has some value. 



Bryozoa Nos. 1 to 5 and 7 to 9 were massive coralline forms and were easily handled. No. 6, 

 Lepralia, was an incrustation upon a pebble, from which it could not well be separated mechan- 

 ically. The entire specimen was therefore weighed, the bryozoan was then dissolved by hydro- 

 chloric acid, and the pebble was weighed again. The solution only was available for analysis, 

 and the usual loss on ignition could not be determined but was necessarily taken by diff'erence. 

 Such an analysis is obviously unsatisfactory but not entirely worthless. Bryozoa Nos. 10 to 

 13 were dehcate mossy or fernlike organisms, and the poor summations of the last two indicate 

 the presence of undetermined saline matter. The high silica in them is evidently due to 

 inclosed sand. If sihca and sesquibxides are rejected and the remainders recalculated to 100 

 per cent the percentages of magnesium carbonate become 12.51 and 12.95, respectively. The 

 magnesia, however, shows no such regularity as regards temperature as appears in our series of 

 alcyonarians and echinoderms. The difference between the magnesian content of the two 

 specimens of Scldzoporella is very striking. What this difl'erence may signify is yet to be de- 

 termined. 



Several other analyses of Bryozoa, complete or partial, are recorded in the literature. Two 

 of them, fairl}' complete, were made by A. Schwager for J. Walther." They arc as follows, 

 both specimens being from the Bay of Naples: 



1 . Eschiira foliuccu . 



2. Lejiralia sp. 



Schwager's analyses of Bryozoa. 



Actual analyses. 



SiOj 0.29 2.39 



(Al.Fe)^ .32 I 1.47 



MgO 1.20 2.22 



CaO 50. 12 j 47.18 



CO, 41. 06 I 39. 51 



Organic matter -f-H^O 6. 88 7. 53 



SiO, 



(Al,Fe)A 

 MRCO3. . . 

 CaCO,.... 



99.87 



100.00 



Reduced analyses. 



0.31 



.34 



2.71 



96.64 



100.00 



2.58 



1.58 



5.02 



90.82 



100.00 



" Walther, J., Deutsch. geol. Gesell. Zcitschr., vol. 37, p. 338, 1885. 



