
sped. «<4 Zoology. 831 
phlogopite from Burgess, Ont., as Al(SiO,),;Mg,KH,+Al,(SiO,),Mg,K 
(MgF). Belowsky* finds that green hornblende, when subjected 
for some time to the heat of a bunsen burner, changes its color, the 
character of its pleochroism, the strength of its double refraction, and 
the position of its planes of extinction, and becomes in all respects 
similar to the basaltic variety. Upon the addition of a little sodium 
chloride #8 to a solution of sodium sulphate, the latter salt crystallizes 
upon evaporation as ¢henardite, and not as mirabilite. A mixture of 
potassium and sodium sulphate under the same conditions yield 
glaserite. A few illustrations of regular growth of pyrite crystals are 
given by Smolar.* Some of the crystals (all of which are from Pied- 
mont and Elba) are probably interpenetration twins according to 
some new law, while others are regular growth only. The author 
believes that our knowledge of twinned crystals is still in its infancy, 
and advises many more observations on regular intergrowths before we 
conclude as to the conditions of twinning. Rhombic pyramids of 
sulphur® crystallize from picoline or pyridine saturated with sulphur- 
etted hydrogen. The oölitic tron ores of the Cliniton group in the 
Alleghenies are not cemented concretions, as was supposed, but they 
are pseudomorphs of bryozoons, or of fragments of these.*! 



ZOOLOGY. 
Sipunculus gouldii.—Dr. E. A. Andrews, in a paper! that should 
have received earlier notice, describes the structure of this common 
east coast Sipunculid. Tle principal points brought out are the rich 
peripheral nervous system ; the presence of ‘‘ pseudostomata-’ in the 
splanchnic epithelium, the function of which remains unsettled ; the 
division of the alimentary ae into Sarian on Merata i 
anatomical and histological p th babili 
is asucking organ ; the confirmation of the ias that the reproduc- 
tive organs were on the posterior surface of the origin of the posterior 
retractor muscles. Andrews thinks that the points which he has 
27 Neues Jahrb. J. Min., etc., en I., p. 291. 
28 Retgers. Ib., r8gr, I., 
29 Zeits. f. Kryst., XVIII., 180, 
30 Ahrens. Ber. 4 deutsch $ sf le Ger XXIII., 1890, p. 2708. 
31 Amer. Journ. Sci., Jan., 1891, 
1 Studies Biol. as “Johns Hopkins eat IV., p. 389, 1890. 





