xv > i Cowles: Habits of Tropical Crustacea $& 



placing them on the new shell, and that the sea anemones aid 

 the hermit in this procedure. 10 



Some zoological text books mention the fact that this trans- 

 planting of anemones has been reported; but the subject, if dis- 

 cussed, is generally treated, whether intentionally or not, as 

 though there might be an element of doubt as to the occurrence 

 of this habit. For the reasons mentioned, and because five of 

 my coworkers and I have seen the transfer for the first time in 

 the case of two species of hermits living in Philippine waters, 

 I shall now record my observations. 



Along the coast of Mindoro Island, in Port Galera Bay, there 

 occur hermit crabs belonging to two species, Pagurus deformis 

 and Pagurus asper de Haan, which inhabit mollusk shells of Do- 

 lidse, Strombidae, Cassis, etc. Both of these hermits almost in- 

 variably carry two different kinds of sea anemones on their 

 shells ; one, a large grayish brown form usually on the sides and 

 another, much smaller, almost colorless form usually on the 

 underside of the mollusk shell below the protruding head of the 

 crab (Plate I). As many as eight of the large anemones and 

 three or four of the smaller kind have been found on a single 

 Dolium shell, but so great a number is rather unusual. While 

 in the majority of cases the small anemones are attached on 

 the underside of the mollusk shell below the head of the hermit 

 and the large ones on the upper and lateral surface of the shell, 

 occasionally specimens are found in which the order is reversed. 



Either the anemones when in the larval condition attach 

 themselves to the mollusk shell carried by the hermit, or they 

 are placed there by the hermit when they are still very small. 

 On one occasion a beautiful, clean shell which was not beach, 

 worn was collected containing a young specimen of Pagurus 

 deformis. On the upper surface of this shell were three of the 

 brown anemones, 2, 4, and 8 millimeters across, and just inside 

 the mouth of the shell was one of the colorless species, 3 milli- 

 meters in breadth. The extreme smallness of the anemones in 

 this case might indicate that they became attached to the mollusk 

 shells in the larval stage, and this is borne out by the fact 

 that in all our collections at Port Galera we have never found 

 these anemones except on shells inhabited by hermits ; but since 



10 Eisig, H., Studien fiber tiergeographische unci verwandte Erschein- 

 ungen, I. Zum Verstandniss des Comraensalismus der Einsiedlerkrebse (Pa- 

 guriden) und Seeanemonen (Aktinen), Das Aussland (1882) 55, 681; 

 Gosse, P. H., op. cit. 



