396 
Miscellaneous. 
of the shell like the Nautili and Ammonites. Persuaded that a care- 
ful investigation of the structure of the Nummulites could alone 
decide respecting the form of the animal which constructed these 
singular habitations, we set earnestly about it, and after frequently 
repeated observations and sections, fractions, sawings and grindings, 
and having examined with the microscope a multitude of Nummulites 
as hard as quartz or the most compact limestone, we had the good 
fortune to meet with a number from which we might remove suc- 
cessively the circumvolutions of the spire by means of a kind of 
cleavage, which has led us to conclude : — 
1. That the Nummulites were external multispiral shells with 
enveloping convolutions, and at the same time polythalamian. 
2. The sides of these shells were perforated in a similar manner 
to what is observed in the Rotalia and Nonionina. 
3. It was through these holes that the numerous tentacula or 
pseudopoda with which the animal was provided were exserted 
(organs of prehension or locomotion). 
4. The septa of the chambers leave a triangular aperture between 
them and the last-formed convolution of the spire by means of which 
they all communicate. 
5. All the chambers were occupied at the same time by the multi- 
segmented body of the animal. 
6. The several segments were connected with one another by a 
tube or sipho, which at the same time fulfils the office of digestive 
canal. 
7. The animal increased by producing new segments which were 
added in the same plane to those previously existing. These seg- 
ments were soon enveloped by the calcareous matter which they 
secreted, like the mantle of the Mollusca. 
8. The inhabitant of the Nummulites was neither a Polyp nor a 
Medusa, nor an Annelide nor a Cephalopodous mollusk, but one of 
those long- misunderstood creatures for which D’Orbigny created the 
name of Foraminifera. — Comptes Rendus, Oct. 25, 1847. 
Description of the Caligus Strdmii. By W. Baird, M.D., F.L.S. &c. 
In 1845 I found upon a salmon at Berwick a species of Caligus 
which, at that time, I thought was new. Upon more careful ex- 
amination I found it approached very near the Caligus Vespa of M. 
Edwards, differing however considerably in size and other more 
minute distinctions. In the Copenhagen Transactions, vol. x. p. 23, 
and t. 7. f. 1-6, the celebrated Strom has described and figured a 
species of Caligus under the name of ” Laxe luus ” or salmon louse, 
and which he shortly defines “ Monoculus thorace abdomineque 
ovato, cauda lobata.” It is evidently the same as the specimens I 
found upon the salmon of the Tweed, and as Strom is the only author 
who seems to have noticed it, I have named it after him. 
without any apparent aperture and internally a spiral cavity divided by septa 
into a number of minute chambers, but without a sipho (Regne Aniinal, 
iii. p. 22) ; which is the same thing as saying, that these chambers had no 
communication wfith each other nor with the exterior. From our examination 
of these fossils we have been led to admit the very opposite. 
