EEFORT OiSr THE HOLOTHUEIOIDEA. 
55 
specimen from ISTew Zealand. A re-examination and comparison of both forms 
is necessary. Even the deposits of the New Zealand form are not exactly like 
those figured by von Marenzeller, their margin bearing mostly roundish knohs 
instead of teeth ; but I even found deposits with more conical teeth-like knobs 
in the same species. 
Caudina caudata [MicrodactyJa)^ Skiiter, 1880; Ludwig 1883. 
Tentacles twelve, terminating in a small disk. Deposits, resembling those in Caudina 
ranzonndii, consisting of regularly perforated cups with teeth in the margin, and 
with the opening closed by an x . 
Hahitat. — Sunda Strait (Sluiter). 
Ludwig feels himself inclined to refer this species to Caudina ranzonndii, but, if so, 
the description of Sluiter must be very incorrect. Indeed, the figures of the 
tentacles are very remarkable, and there seems to be but little doubt that they 
are incoivectly drawn and understood. On the other hand, his statement of the 
number of tentacles may probably be right, and the calcareous cups of the 
respective species differ from one another in an obvious manner. However, 
Caudina caudata may be ranged among the unsatisfactorily known forms. 
Gemis 6. Molpadia, Cuvier, 1817 ; Semper, 1868. 
Retractor muscles present. Calcareous ring with five bipartite posterior prolonga- 
tions. Tentacles twelve to fifteen, branched, digitate. Calcareous deposits — 
knobbed or spinous, perforated, roundish button-like disks. 
Molpadia chilensis, J. Muller, 1850, 1854. 
Tentacles twelve to fifteen, each with four digits. Deposits — very regularly formed, 
rounded buttons with symmetrically arranged rounded knobs and four central 
holes. 
Hahitat. — Chili (Muller). 
Molpadia australis, Semper, 1868. 
Tentacles fifteen, with four digits. Deposits irregularly formed, roundish buttons 
with asymmetrically placed (up to seven) holes, and with short spines in the 
margin as well as on their surfaces ; besides, scattered calcareous rods in the 
deeper layer of the skin. 
Hahitat. — Rockhampton (Semper). 
