8 CLAVID^. 



skirts of the group, where they are youngest, each one 

 may be traced separately." 



The polypites are "highly contractile, and capable of 

 assuming a variety of shapes." When very lively the 

 body " is stretched to the utmost, with elongated head and 

 extremely attenuated tentacles ; at other times . . . the 

 head is depressed to a flat-topped disk, from which the 

 tentacles radiate nearly in one plane, like the spokes of a 

 wheel." " When disturbed, the whole body assumes the 

 most contracted condition; the stem and head shorten, 

 and the tentacles retract towards their bases, even to such 

 an extent as to be only three times longer than thick, 

 whilst the inner surface of the chymiferous cavity becomes 

 deeply plicated in obliquely transverse folds, which look 

 like spiral semipartitions." This was very apparent in 

 my specimens*. 



The gonophores are borne on pedicels, 10, 15, 20, or 25 

 of which " spring from a large, thick and short peduncle, 

 which projects directly from the sides of the body. This 

 form of grouping may be compared to a very short raceme, 

 as the term is used in reference to plants. Usually these 

 bunches are attached to the stem, nearly on the same 

 level, and just below the tentacles; but frequently the 

 crowded groups extend downward, either continuously or 

 in detached masses, over one-third of the distance towards 

 the base/ 3 



Agassiz speaks of Clava leptostyla as forming "little, 



* Montagu, in an unpublished work now in the possession of the Linnean 

 Society, mentions a similar peculiarity as presented by a Clava which he 

 identifies with the Hydra squamatu, and had found on the leaves of Fucus 

 vesiculosus in the estuary of Kingsbridge, South Devon. " When examined 

 by a lens," he says, " the intestinal canal is observed to be undulatory or 

 spiral, and appears to be the coloured part of the body, the exterior part 

 being hyaline." This is the only record, I believe, of the occurrence of a 

 clustered Clam in Devon ; and it is not improbable that the species observed 

 by Montagu was the C. leptosfyla. 



