36 THE AUSTRALIAN MUSEUM. 



The test on section and inner surface is like that of a typical Micro- 

 cosmus. The muscle bundles of the mantle form a rather loose irregular 

 network. The branchial sac is of a yellow colour with 9 wide folds on 

 each side, and there may be a 10th very slight fold next to the endostyle. 

 The transverse vessels are rather irregular in their arrangement (fig. 9) . 



The languets form a continuous row bordering one edge of a flat 

 membranous area, which runs along the dorsal edge of the branchial 

 sac ; but there are also a few slighter languets (fig. 8) placed here and 

 there along the other edge of the membranous area, and corresponding 

 to transverse vessels of the branchial sac. 



[The following Cynthiinae have also been recorded from Australia : 

 Microcosmns polymorphus, Heller. 

 M. Helleri, Herdm. 

 M. propinquns, Herdrn. 

 M. Julinii, v. Dr. 

 M. distans, Heller. 

 Ehabdocynthia complanata, Herdm. 



B. tennis (?), Herdm. 

 E. sp. (?), Sluiter. 

 Cynthia arenosa, Herdm. 



C. formosa, Herdm. 



C. cerebriformis, Herdm. 



C. irregularis, Herdm. 



C. fissa, Herdm. 



C. arcuata, Heller. 



C. grandis, Heller. 



C. hispid a, Herdm. 



C. dumosa, Stimps. 



C. sabulosa, Stimps. 



C. laevissima, Stimps. 



and probably the following species placed under Ascid-ia by Quoy and 

 Gaimard: A. aurora, A. reticulata, A. erythrostoma, A. ianthinostoma, 

 A. ccerulsa, A, spinosa.] 



Sub-family STYELINJE, Herdman, 1881. 



Body attached, sessile, rarely incrusted with sand. Branchial and 

 a trial apertures either 4-lobed or irregular. 



Test usually coriaceous, rarely cartilaginous. 

 Branchial sac with at most 4 folds upon each side. 



