376 SPECIES OF THE SYSTEMA. 
the shell there represented is described as being spirally 
banded with black upon a yellowish ground; the “t. 572, 
f. 23” after “Sloan Jam. t. 1, f. 4,” should have been preceded 
by “ List. Conch.;” and the “ Acta Angl. 301, p. 2051” was a 
typographical mistake. 
Helix bibipara, 
So ill executed were most engravings of natural-historical 
subjects in the days of our author, that he was constrained to 
make allowances, in his references to them, for far greater 
aberrations from the typical characters of his specimens than 
we, in the present era of copious and accurate illustrations, 
should think of admitting. Hence, probably, it has occurred, 
that in addition to that Paludina (P. achatina of Turton, Ross- 
miissler, &c.) which he has marked in his collection as the type 
of H. vivipara, and cited among his iconographic references 
(List. Conch. pl. 126, f. 26, which is a fair representation of the 
Linnean examples), he has also included the Paludina vwipara 
of Turton, C. Pfeiffer, Rossmiissler, &c., in his synonymy. 
That species, so far from being “imperforata,” is clearly um- 
bilicated (as, in truth, are large individuals of achatina ; not so 
the Linnean examples), but the quoted drawings do not suffi- 
ciently exhibit that feature to render their citation either un- 
natural or reprehensible: its contour, however, is so much 
more abbreviated than in the typical species, that the expres- 
sion “ oblongiuscula” (Fauna Suecica, edit. 1) would have been 
most inappropriate. Although, then, we cannot believe that 
Linneus would have held the essential distinctions as of more 
than varietal importance, we are compelled, alike by the evidence 
of his type and of his language, to transfer the name vivipara 
from that which has commonly received it to its allied congener 
P. achatina. 
I take this opportunity of rendering the terminology of 
Linneus more clear by adverting to his use of the word 
longitudinal, without the due comprehension of which expres- 
sion his meaning becomes occasionally difficult to understand. 
In general he has used it as equivalent to vertical or parallel to 
