35 
even the entire dead body of a Spirilla. This was just as 
unavailing as the many searches which my three travelling 
companions and I made on our marine excursions, and among 
the masses of Spirilla thrown upon the shore. It is certain 
that the Spirilla only reaches the Canary Islands very rarely, 
if at all, in a living state, since all the fishermen uniformly 
assured us positively that the well-known Spirula shells were 
always, (lead, and that they never enclosed or were inhabited 
by a living animal. All that I could procure were some 
white remains of the encompassing mantle, adhering to a 
few shells which, however, did not enable me to ascertain 
anything of the structure of the body of the Spirula. These 
unsatisfactory remains ivere frequently driven into the har- 
bour of Arrecife, and on some days a strong south wind 
would drive ashore unusually large quantities of empty 
Spirula shells, along with numerous Physalia, and Yelella, 
and other pelagic animals of the island Lanzarote. 
Although my hopes respecting the Spirula itself were not 
fulfilled, I nevertheless found on the empty calcareous shells 
of this cephalopod driven ashore in January, 1867, a Pro- 
tozoan organism of the Mouera group, which was of the 
greatest interest to me, and whose life-history I have delineated 
on Plate IX. 
As I sought carefully for some remains of a mantle still 
adhering to the shells, among a great quantity of Spirula 
shells which were floating on the surface of the harbour of 
Arrecife, and which I had drawn up in a bucket along with 
Physalia, Abyla, Hippopodius, and other pelagic animals, I 
noticed an empty Spirula shell, whose ordinary, shining por- 
celain-white was obscured, in several places, by small red 
flakes. Under a strong lens these flakes were seen to be 
partly in groups of thickly-placed very small red dots, and 
partly in extremely fine ramifying arborescent figures. 
The red dots were easily detached from the surface of the 
Spirula shell, with needles, under the dissecting microscope. 
With a higher magnifying power each dot resolved itself 
into a tolerably opaque, orange-red ball, covered with a 
thick structureless membrane. The diameter of the whole 
body measures in most 0T5 mm., in the largest 0'2 mm., in 
the smallest 0T2 mm. (PI. IX, fig. 1). The membrane of 
the ball appeared entire, structureless, glassy, colourless, and 
translucent. Only a number of (from five to ten) very fine 
parallel striae were to be noticed, which ran concentrically 
round the centre of the ball, apparently indications of the 
separation of the structureless mass into layers. Radiating 
striae, pore-like formations, or other openings, were not ob- 
