ON PETRICOLA PHOLADIFORMIS. ; 241 
on the Belgian coast '), and also at Dunkerque °) in France. In 
June 1906 Miss H. Icke ( presently Mrs. Martin—Icke) found 
this species on the Dutch coast near Noordwyk*). In the 
same year it was noticed by Mr. Caesar R. Boettger *), 
by Mr. B. Wolf*) and by the Rev. Ricklefs®) on different 
points near the German coast, from the Dutch till the 
Danish frontier. Mr. Julius Pfeffer®) mentioned the 
occurrence near Hooge, a small North Frisian island, south 
of Föhr, and stated the fact that this species never occurred 
there before 1906. Finally Mr. H. Schlesch’) obtained it 
in 1907 from Fanö and Manö, two Danish islands. Seeing 
thus, that Petricola pholadiformis has a rather wide distri- 
bution on the North-Sea-coast, and that it is found rather 
abundantly near our frontiers, I expected a priori that 
Mrs. Martin’s statement should not remain the only one. 
When examining the collections of shells from our country, 
acquired by the „Rijks Museum van Natuurlijke Historie” 
during the last years, I actually found several specimens 
of Petricola pholadiformis from various localities along 
the coast. They are the following: 
Domburg, isle of Walcheren, 1905, Mr. W.C. van Heurn ; 
1912, Mr. J. H. Vernhout. 
Renesse, isle of Schouwen, 1911, Mrs. H. Martin —lcke. 
Scheveningen, 1905, Mr. W. C. van Heurn. 
Katwijk, 1909, Mr. W. C. van Heurn. 
1) P. Dupuis et S. Putzeys. Annales Soc. royale Zool, et Malacol. de 
Belgique, 1902, Tome XXXVII, p. IV. 
P. Pelseneer, Association francaise pour Vavancement des Sciences. Comptes- 
rendus et Mémoires, Angers, 1903, Vol. II, p. 774. 
2) Bouly de Lesdain. Feuille des jeunes Naturalistes, 1906, IVe série, 37e 
année, p. 20. 
3) H. Icke. Tijdschrift der Nederl. Dierk. Vereeniging, 1907, 2de serie, 
deel X, p. 226. 
4) Caesar R. Boettger. Zoolog. Anzeiger, 1907, Band XXXI, p. 268. 
5) Ricklefs. Nachrichtsbl. der Deutschen Malakozool. Ges. 1908, 40. Jahrg. 
p. 41. 
6) Julius Pfeffer. Nachrichtsbl. der Deutschen Malakozool. Ges. 1911, 43. 
Jahrg. p. 67. 
7) H. Schlesch. Flora og Fauna, 1907, p. 73. 
Notes from the ‘Leyden Museum, Vol. XXXIV. 
16 
