Reviews—Paul Choffat—Paleontology. av 
V.—Description DE LA Faunr Jurasstque pu Portucat. Mot- 
LUSQUES LAMELLIBRANCHES. Par Paut Cuorrat, Premier Ordre 
Siphonida Premiére Livraison. Pages 1 4 39 et Planches I. 4 IX. 
Lisbonne, 1893. 
7H do not appear to get much in the way of geology from 
Portugal, but what we do get is good. Here is another 
instalment of the description of the Jurassic Fauna by one whose 
previous contributions in the same direction have given us every 
confidence in their value. This particular section plunges at once 
im medias res and gives us a Monograph of the Jurassic Pholadomye 
of Portugal. The difficulties under which work is done in that 
country is curiously revealed by the few words of Preface, from 
which we learn that the text and plates were all ready in 1883, 
except plate i., which was intended to illustrate family matters, 
i.e. the families of Pholadide, Myide, and Anatinide; but the 
author had no artist at his disposition! Even now the plate is 
used, not as intended, but for new species of genera allied to 
Pholadomya. It is certainly a question whether this curious lack 
of artists is not a blessing in disguise, for the result is that the nine 
beautiful plates are all photographic representations, in permanent 
phototype print, of the actual specimens; nothing whatever in them 
is liable to the personal equation. This is, perhaps, specially advan- 
- tageous in the case of such rough things as Pholadomye, where so 
much depends upon the shape, the strength, or otherwise, of the 
ridges, on the cardinal area and the character of the radiating 
ribs. And for another reason, as will be seen presently, it is a good 
thing to have as many figures as the author will give us of the 
Portuguese forms. 
It appears that the Lias, at least, presents two distinct facies—one 
in which the succession can be fairly compared with that in Central 
Kurope, and the other peculiar to the Iberian Peninsula. As several 
species of the Pholadomye occur in both, this should be an aid in 
correlation. 
When, however, we come to examine this work in detail we get 
into a little difficulty. There always have been two types of 
Paleontologists: the one type divides and subdivides till almost 
every Specimen is a species, and if there is any character common 
to them all, other than the one on which he has set his affections 
as the discriminator, they are said to show a remarkable “con- 
vergence,” they are ‘‘homoplastic,” ‘morphological equivalents,” 
and all the rest of it. The other type seizes, perhaps, this very one 
of all the characters, as the bond of union into a “good species” 
of forms of which it may at least be said that if one gave birth 
immediately to the other the offspring would be considered a 
monstrosity. The one type also so subdivides the strata in which 
these fossils lie that the successive species must be as crowded in 
their “beds” as a family in a London slum; while the other gives 
his species so great an immortality that it crops up in formation 
after formation. Which of these two types will gain the ultimate 
victory, or whether both will be united or swept away by something 
more comprehensive, it is hard at present to say. 
