REPOET ON THE TETEACTINELLIDA. 
181 
Pilochrota (f) lactea (Carter). 
Stelletta lactea, Carter, Ann. and Mag. Nat. Hist., ser. 4, vol. vii. p. 9, pi. iv. figs. 17-21. 
„ „ Norman, Mon. Brit. Spong., Bowerbank, vol. iv. p. 210, 1882. 
Sponge small, filling small excavations made on rocks by Saxicava and other boring 
animals. 
Spicules. — I. Megascleres. 1. Oxea, 1‘25 mm. long. 2. Orthotriaene and dicho- 
triaene, 0‘825 mm. in length. 
II. Microscleres. 3. Spheraster, minute, centrum of variable size, sometimes almost 
absent, sometimes of much greater diameter than the length of the actines ; actines 
numerous, slender, oxeate, truncate, or rarely tylote ; 0'0125 mm. in diameter. 4. 
Orthodragma, confined to the choanosome, 0'025 mm. in length. 
Colour. — White externally. 
Hahitat . — South Devonshire. 
Remarks. — As I am ignorant of the structure of the cortex of this species it is with 
considerable hesitation that I place it in the genus Pilochrota; the orthodragmas, as 
stated by Carter, are confined to the choanosome, and there is no necessity therefore to 
assign it to Dragmastra, with which it is evidently not nearly related. 
Astrella anceps (0. Schmidt). 
Stelletta anceps, 0. Schmidt, Spong. Adriat. Meeres, Suppl., iii. p. 31, 1868. 
Spongeiormmg irregular crusts; cortex from 0‘8 to r6 mm. in thickness, apparently 
not differentiated into two layers ; surface hispid. 
Spicules. — I. Megascleres. 1. Oxea, 178 by 0‘045 mm. 2. Orthotriaene, 1'25 mm. 
in length ; esactine frequently shortened and strongylate ; cladi 0742 mm. long. This 
spicule is frequently reduced to a disene. 
II. Microsclere. 3. Pycnaster, from 0'013 to 0'02 mm. in diameter (0‘0098 mm., 
0. Schmidt) ; this is a remarkably variable form, passing into oxyasters, chiasters with 
bacillary truncate actines and spherasters, without, however, changing its size. 
Colour. — Cortex violet. 
Habitat. — Cette, Algiers. 
Remarks . — This sponge is very closely allied to Astrella pumex, from which it is 
distinguished by the difference in the form of the cladome of the trisenes. I have 
provisionally assigned it to the genus Astrella, but am much inclined to think that its 
better place would be with Pilochrota. 
