what are termed the egg-bearing organs, consequently, if those are the females that are thus distinguished, they prove much more numerous than the males.

The tegument covering the body is soft and yielding, the appearance of segments and articulations are necessarily faint, indicating that little motion of the parts is required.

They are to be found in considerable numbers in connexion with the fuci, thrown up by the waves along the shores of the islands, after being detached by the motion of the large masses of ice, from the bottom of the sea.

PLATE VII.

Fig. 1. Superior view of the animal, natural size.

2. Inferior (6

prived of the legs near the coxæ.

66

de

ART. XII-CHEMICAL ANALYSIS OF CHRYSOCOLLA FROM THE HOLQUIN COPPER MINES, NEAR GIBARA, CUBA. By C. T. JACKSON, M. D. Read May 6, 1835.

MR. JAMES DAVIS, Jr. presented me with several ores of copper, from the mines recently explored in Cuba, for chemical analysis. Among these ores Iobserved a beautiful green ore, similar to the mineral described in works on mineralogy as Chrysocolla. It occurs in botryoidal and mammillary incrustations in the cavities of Bronzite or Diallage rock. Some of the incrustations are an inch or more in thickness, and when the mineral is broken, it

exhibits a perfect conchoidal fracture. It yields to the knife, but scratches glass readily. It is brittle. Its powder is nearly white, having a slight tint of green. It adheres to the tongue, and absorbs water when immersed in that fluid. It takes a good polish, which it preserves when the surface is oiled.

Sp. Gr. = 2.16. When a fragment of the mineral is treated with carbonate of soda on charcoal before the blow-pipe, it melts with effervescence, and a globule of copper is obtained. A portion of the mineral being powdered and treated with muriatic acid, no effervescence took place, but oxide of copper dissolved, leaving silica, insoluble, behind.

ANALYSIS.

A. To ascertain the quantity of water contained in the mineral, 25 grains in powder were subjected to a red heat in a platina capsule. It lost 8.25 grains, equal to 33 per cent. of water.

B. Twenty-five grains of the powdered mineral, in a glass flask, were subjected to the action of muriatic acid, and the digestion was continued 48 hours on the heated sand bath, the acid being removed and renewed until it ceased to dissolve any thing. The solution was then diluted largely with water, and the whole thrown on a filter, to separate the silica, which, collected, washed, dried, ignited and weighed, amounted to 7.5 grains, equal to 30 per cent. of silica.

C. The solution which had passed the filter with the washings of the silica was treated, while boiling hot, with a hot solution of pure potash and boiled. A dense, black precipitate took place, consisting of deut-oxide of copper, which, collected on a filter, washed, dried, ignited

in a platina crucible, and weighed, amounted to 9.25 grains.

The oxide of copper was re-dissolved in muriatic acid. diluted with water, when 0.12 grains of silica remained undissolved, which is to be added to the silica obtained by process B. The solution was now supersaturated with pure ammonia, when oxide of iron separated, which, collected, washed, dried and ignited, did not amount to more than 0.05 grain per oxide of iron.

This ore consists, then, in 100 parts, of

From which it will appear that this ore is a bi-silicate of the deut-oxide of copper plus 4 atoms of water, and its chemical formula will be

Cu Si+ 4 Aq.

The per-oxide of iron is evidently accidental, having been derived from the gangue in which the mineral occurs. This ore is of great value, as its silica renders it suitable to aid in the reduction of the black sulphuret of copper and iron which occurs at the same place; the silica combining, in the metallurgic operations of reduction of the copper, with the iron, which is thus separated in the slag from the copper, which collects at the bottom of the furnace. This green ore has lately been brought to Boston by the cargo, and it is also carried from Cuba to Swansey, in England, where it is used with the black sulphuret to aid in the process of reduction of that ore.

BOSTON

JOURNAL OF NATURAL HISTORY.

VOL. I.

MAY, 1836.

No. 3.

ART. XIII.-DESCRIPTIONS OF NEW SPECIES OF NORTH AMERICAN HYMENOPTERA, AND OBSERVATIONS ON SOME ALREADY DESCRIBED. BY THOMAS SAY. Communicated Feb. 1835.

FAMILY TENTHREDINETÆ.

Genus ACORDULECERA, Say.

ARTIFICIAL CHARACTER.

ANTENNE filiform, 6-jointed, short; radial cellule one; cubital cellules three, the second smallest.

NATURAL CHARACTER.

Antennæ six-jointed; 1st and 2d joints subequal, the second larger; third joint longest but equal to the following ones in diameter; remaining joints gradually shorter; terminal joint not longer than the second: mandibles arcuated, acute; a prominent tooth on their middle: labrum prominent and distinct: radial cellule rather large cubital cellules three; first elongated, as long

again as the second: carpus large: tibiæ with one pair of spines at tip.

OBSERVATIONS.

The family of which this new genus is a member, was divided by Leach into 9 Stirpes, all of which have 9 or more joints in the antennæ excepting the 1st, 2d, and 5th. Of these, two genera only, have 6-jointed antennæ, viz. ZAREA and PERGA, Leach; but both have clavate antennæ and in many respects are at variance with the characters of the present insect. In a later work, the "Entomologische Monographieen," by Dr. Klug, which that author has done me the favor to send me, are the two new genera PACHYLOSTICTA and SYZYGONIA, both of which have clavate antennæ, and therefore, like the preceding, cannot possibly include our insect.

SPECIES.

A. dorsalis. Black; hypostoma, a base of the tergum and feet whitish.

Inhabits Indiana.

Black, with minute whitish hairs: nasus, labrum and mouth white mandibles rufous at tip: thorax with the anterior segment, curving to the base of the wing, white; line of the insertion of the wings white: wings a little dusky; nervures fuscous: tergum pale yellowish on the basal disk, blackish brown at tip: venter more or less yellowish-white, dusky or blackish at tip: feet and coxæ whitish-green.

Var. a. Feet and part of the costal rib green; scutel and posterior portion of the stethidium whitish.