58 Bulletin Vandcrbilt Marine MiLseum, Vol. VII 



The species is placed provisionally in the genus Veretillum, 

 Cuvier (1798) , although the writer is quite aware that the present 

 species, V. vanderbilti, possesses in addition to the "thin plate 

 spicules" accepted as typical of the genus Veretillum, the smooth 

 needle-shaped spicules, sometimes branching at the extremities, 

 considered distinctive of the genus Cavernularia Valenciennes, 

 Milne Edwards et Haime (1857), and likewise possesses "rod- 

 shaped" or "flattened needle-shaped ridged spicules" diagnostic of 

 Actinoptilum Kukenthal (1910), while the denticulate spheroidal 

 or ovoidal spicules of the cutis of the rachis of V. vanderbilti are 

 but a slightly more primitive form of the "double club" or dumb- 

 bell" shaped thorny spicules typical of the genus Lituria Valen- 

 ciennes (1850). 



The alternative of designating a new genus within the group 

 seems most undesirable, in view of the existent variability of char- 

 acters accepted for those genera comprising the Veretillidae. 



Colour : Mr. Vanderbilt's colour notes state : "Colour of naked 

 part orange-yellow, body pink-salmon, tubes of polyp transparent, 

 tentacles yellow." 



Technical description: The single well preserved colony 

 gives the following measurements, all expressed in millimeters : 

 Total length 300, length of stalk 50, maximum diameter of bulb 

 35, length of trunk 250, average diameter of trunk 30. 



The colony is cylindrical, the proximal sixth forming a spongy 

 stalk, distinctly bulbous, the trunk being rather evenly dilated, 

 moderately tapered on the distad fifth, the apex rounded and 

 crowned with numerous large autozooids ; the coenchyma is firm, 

 compact. The autozooids are large, distributed over practically 

 the entire surface of the trunk, with the numerous siphonozooids 

 crowded in the interstices. The autozooids occur in practically 

 all stages of expansion and retraction, being capable of complete 

 retraction within the cuplike base ; a typical average large auto- 

 zooid expanded is shown in plate 12, figure b. 



The expanded portion of an autozooid has an average antho- 

 codia length (in millimeters) of 14, disk diameter of 5, tentacle 

 length 5 (measured additional to the length of the anthocodia), 

 basal pinna 0.8 and distal pinna 1 to 1.2 long. There are eight large, 

 pinnate tentacles each side of a central tentacle, the cavity of the 

 tentacle extending within the pinnae, which normally increases 



