A. EF. Verrill on the Mollusca of Europe and N. America, 471 
landica a variety of A. compressa; but I have already shown 
(Amer. Journ. of Science, April, 1872) that it is a variety of A. 
quadrans. His arrangement of the other species of Astarte is 
“sng objectionable, but it is not necessary to discuss them 
ere 
The Pecten fuscus Linsley is given as the young of P. irradi 
ans, from which it is very distinct; but the writer has shown 
Amer. Journ. of Science, vol. ii, p. 361, and vol. iii, p. 218, 
1871~72) that it is really the young of P. tenuicostatus, 
ekay is given as the authority for Zolis sulmonacea and A). 
gymnota ; but they were both described by Couthouy in 1838, 
from whom Dekay borrowed both the descriptions and figures, 
five years later. 
He states that Deutalium dentule (non Linn.) is a variety of 
Entalis striolata, and that the latter is a variety of D. abyssorum 
ars; but both of these statements are incorrect. The first is 
the Dentalium occidentale Stimpson, and is a true Dentatium, 
entirely different, generically and specifically, from the striolats; 
and the latter is also quite distinct from abyssorum. Possibly 
Mr. Jeffreys has not seen perfect specimens of all the American 
Species ; otherwise, I cannot understand ‘how he could have 
made these statements. 
He is correct in considering Crepidulu glauca a variety of € 
Sornicata, as others have done before him; but he has adopted 
which it is really very distinct. It isa very common error to 
€qual in size, from Labrador. ; 
There is no sufficient reason for adopting the name Lacuna 
divaricata in place of L. vincta ; for it is not the Trochus divart- 
catus of Linné (1767), although it is the shell described under 
the same name by Fabricius in 1780, as shown long ago by Dr. 
Stimpson and others. Fabricius made a mistake which we 
have no right to perpetuate; nor does “ usage,” to which Mr. 
Jeffreys so often appeals, sanction the — 
The Zunatia triseriata is not, as Mr. Jeffreys thinks, the 
young of ZL. heros, but only a color-variety, as the writer had 
previously shown (April, 1872). Both varieties occur together, 
