Miscellaneous. 41 1 



Spicula. — The characteristic spicule is that figured by Grube 

 (' Die Insel Lussin unci ihre Meeresfauna,' 1864, fig. 7 a) and 

 Jeffrey Bell (Cat. Echin. pi. vi, fig. to left and more magnified above), 

 usuallj' with four foramina and some nodules on the surface and edge ; 

 they may be regarded, as Theel observes, as imperfect " tables," the 

 legs being undeveloped — but rarely the foramina are more nume- 

 rous and the legs are in some measure developed. This characteristic 

 spicule is sparingly scattered over the dermis. 



Ventral pedicels. — The stem m ith no other spicules than of the 

 characteristic form, but the disk capped with a large cribriform 

 plate (the foramina of which are not arranged in any regular order) ; 

 round the base of this terminal plate the pedicel is surrounded with 

 a circlet of elongated spicula, with foramina more or less developed 

 in a row on each side of the central axis (figured by Bell, fig. 5, to 

 right). 



Dorsal papilhe are white with a black tip. Some little distance 

 beneath the dermis is a hollow coil composed of slightly curved rod- 

 like spicules, which in their central portion are smooth and round in 

 section and have their ends expanded and commonly rounded, pierced 

 either with a few foramina or nodulous. Overlying this coil are 

 spicules of the characteristic type, but mixed here with others of a 

 modified and larger size, having eight or even more foramina, the 

 additional foramina having been built on to the sides of the original 

 spicule after the usual manner of spicule growth. 



Tentacles invested with spicules which are large towards the 

 base and gradually smaller distally, to correspond with the lessened 

 size of the ramification of the tentacle ; spicules arcuate or, more 

 rarely, straight rods, their central portion roughened with a few 

 nodules or blunted spines, the extremities attenuated, rugose with 

 crowded little nodulous points ; occasionally at the extremity and 

 sometimes on central portion minute foramina are to be seen ; such 

 perforated spicules are somewhat flattened instead of round in 

 section. 



Marenzeller is mistaken in supposing that this species does not 

 attain so large a size in the Atlantic as in the Mediterranean. 

 Some beautifully preserved specimens sent to me from the Plymouth 

 Laboratory measure over 8 inches in length. 



The total absence of the oval spicules which Theel calls " buttons " 

 at once distinguishes this species from //. fubulosa, II. Stellati, H. 

 Sanctori, II. lleUeri, and //. impatiens of the Mediterranean, with all 

 of which I have compared it ; while the absence of the fine " tables " 

 of the northern //. tremula and II. intestinalis makes it impossible 

 to confound it with those species. 



