256 



J. H. ORTON. 



In the same way large hauls of E. esculentus and E. acutus and relatively* 

 large hauls of Echinocardium cordatum can frequently be made on certain 

 grounds in hauls of not more than 10 to 15 minutes, but it is equally 

 uncertain here, as in the case of the dredged E. miliaris, that there is 

 any association in pairs; nevertheless it is not improbable that the 



Fig. l.f — A view of Patella showing the food-paths it has eaten in a growth of green algfe, 

 chiefly young Enteromorpha (s- natural size). 



The limpet is shown on its "home," from which it has made excursions in 

 various directions and to which it has afterwards returned. 



aggregation of such large numbers of individuals might be in part for 

 the purpose of spawning, since such hauls may be taken when all these 

 species are ripe. 



Tennent has observed J in Toxopneustes that " when these animals are 



* Echinocardhun cordatum when living in deep water inhabits fine sand, from which it 

 can only be captured by means of a dredge, and in a 3-foot dredge a short haul may some- 

 times yield as many as 15 individuals. This species occurs in great numbers in the 

 Salcombe estuary within a very small area, but this aggregation is probably due more to 

 the presence of only a small area of suitable ground than to a desire of the individuals to 

 associate. Nevertheless in this locality these heart-urchins associate closely in groups of 

 twos, threes, and sometimes in larger numbers. The sexes of the members of such groups 

 have not, however, been observed. 



+ I am indebted to Mrs. Ortou for the drawing for this figure, v.'liich has been copied 

 from a sketch made in my collecting book. 



X D. H. Tennent, Journ. Exp. Zool., Vol. IX, No. 4, p. 659, 1910. 



