EEPOET ON THE HOLOTHUKIOIDEA. 
137 
Thyone aurantiaca {Uroxia), Costa, 1869; von Marenzeller, 1874; Ludwig, 1880.. 
Haplodactyla mediterranean Taschenberg, 1879. 
Tables present only in the posterior extremity of the body, composed of a disk pierced 
with about four larger and four smaller holes ; their spires made up of two 
anastomosing rods. 
Habitat. — Mediterranean Sea (v. IMarenzeller, Greeff, Ludwig). 
" Porcupine ” Expedition. — Three specimens from Tangiers Bay, which probably belong 
to this species, though their deposits were destroyed. The calcareous ring 
completely resembles that figured by Ludwig. The species must be very closely 
allied to Thyone fusus. 
B. Anus devoid of calcareous teeth. 
I. Calcareous ring of ten simple pieces, without posterior prolongations. 
1. xVo deposits in the hody-ivall itself. 
Thyone meridionalis, Bell, 1883. 
Pedicels “ absent from the greater part of the bivial surface, well enough developed 
above, and diminishing in number on either side as they approach the bivium.” 
Very sparsely distributed rods in the pedicels. Tentacles nearly equal. 
Habitat. — Strait of Magellan (Bell). 
The species is doubtless nearly allied to Thyone spcctabilis. 
2. Deposits present under several fo7'ms. 
Thyone rosacea, Semper, 1869. 
Deposits — cruciform bodies and minute grains. Pedicels with long, straight, smooth 
rods, with the slightly dilated ends branched. 
Habitat. — Aden (Semper). ' 
Thyone cunninghami, Bell, 1883. 
Deposits — delicate rods, often pitchfork-shaped, or swollen and perforated at their 
ends, sometimes more irregular in form. Anus fringed with papillcC. 
Habitat. — Off Dungeness, Patagonia (Bell). 
This species may probably be only a Thyone spectabilis. 
(ZOOL. CHALL. EXP. — PART XXXIX. — 1886.) 
Qq 18 
