EEPORT ON THE TETEACTTNELLIDA. 
189 
II. Microscleres. 4. Ectosomal sanidaster, 0'008 mm. in length. 5. Somal chiaster, 
actines slender, terminally tylote, each 0'008 mm. in length. 
Colour . — Sky-blue ; Ancorina verruca in the dry state brown. 
Habitat. — Zara, Quarnero, in the Adriatic (c), and Porto Kimen, Island of 
Cherso {v). 
Remarks. — The species Ancorina verruca, 0. S., was founded on a single specimen, 
and in its minute structure I can distinguish no character by which it can be separated 
from Ancorina cerebrum. 
Ancorina voageneri (0. Schmidt). 
Stelleita wageneri, 0. Schmidt, Spong. Adriat. Meeres, p. 46, pi. iv. fig. 3, 1862. 
Stelletta immunda, O. Schmidt, Ib. 
Sponge. — Subglobose, about 2 inches in diameter, with an irregular central closed 
cavity. Cortex about 2 mm. in thickness, the outer layer (widely excavated by inter- 
cortical cavities) is from 0'625 to 0'7 mm. in thickness, and the fibrous inner layer 
P27 mm. 
Spicules. — I. Megascleres. 1. Oxea, 2’856 by 0’064 mm. 2. Dichotriasne, rhab- 
dome 3’4 by 0'058 mm., protocladus 0‘058, deuterocladus O'l mm. in length. 3. Ana- 
trigene, rhabdome 3'4 by 0'035 mm., cladus 0T65 mm. long, chord 0175 mm. 
II. Microscleres. 4. Ectosomal sanidaster, 0’008 mm. long. 5. Somal chiaster, 
with slender tylote actines, a single actine 0’008 mm. long. 6. Choanosomal oxyaster, 
centrum not differentiated, actines few, large, conical, usually sharply pointed, a single 
actine may attain a length of 0’045 mm., average length 0'032 mm. 
Colour. — Apparently bluish in the fresh state ; due to the presence of large oval 
cells, with thin walls, of a deep brown colour in the dried state; 0‘06 mm. in 
diameter. 
Habitat . — Quarnero, Adriatic, 
This species is distinguished from Ancorina cerebrum, 0. Schmidt, by the presence 
of choanosomal oxyasters. 
Genus 13. Tethyopsis, Stewart, 1870. 
Non Zittel, Abhandl. d. II, CL k. haier. Akad. d. Wiss., xiii., ii., p. 9, 1879. 
Sanidasterose Stellettidm provided with a special excurrent tube ; the existence of 
a special incurrent tube is doubtful ; the four chief excurrent canals are tetragonally 
arranged. The megascleres of the excurrent tube are modified orthotrisenes. The 
microscleres are spherasters, chiasters, and orthodragmas ; sanidasters are absent. 
