638 PEor. w. A. herdman's eevised 



, r Branchial sac folded ; colony discoid. G. placenta, Herf 



I Branchial sac not folded; colony not discoid 



f Colony rounded or pyriform, pedunculated. [Mag.) 



2 



G. pedunculata, Herdm. (S. Atl., 



1 Colony elongated or irregular, sessile. 

 G. coccinea, Cunn. (Mag.) 



OcuLiisrAErA, Gray, 1868. 



Colony massive, erect, elongated. 

 Test solid, coutaining sand-grains. 

 Ascidiozooids completely imbedded in the test. 

 This imperfectly described genus contains a single species, 

 Oculinaria australis, Grray, from the western coast of Australia. 



Suborder III. ASCIDIJE LJJCIM, Sav., 1816. 

 (Asc. Salpieoemes, Auct.). 



This group contains free-swimming pelagic Ascidians whicb 

 reproduce by gemmation so as to produce colonies having tbe 

 form of a hollow cylinder closed at one end. The ascidiozooids 

 forming the colony are embedded in the common test in such a 

 manner that the branchial apertures all open on the outer sur- 

 face, and the atrial apertures on the inner surface next to the 

 centra] cavity of the colony. The first four ascidiozooids are 

 produced by gemmation from a rudimentary larva (the cyatho- 

 zooid) developed sexually. 



The Ascidiee Luciae include a single family, the Pyrosomidse, 

 containing one well-marked genus, Pyrosojna. 



Family PTEOSOMID^, T. B. Jones, ]848. 



Colony free-swimming, and having the form of a hollow cylinder 

 closed at one end. 



Systems — only one present, the terminal aperture of the colony 

 being the common cloacal opening. 



Ascidiozooids elongated antero-posteriorly, and placed in a 

 single layer with their branchial apertures opening on the surface 

 of the colony, and their atrial apertures into the axial tube or 

 common cloaca. Body of ascidiozooid not divided externally 

 into regions. Apertures not lobed. 



Test gelatinous and transparent, containing no spicules, but 

 many small cells. 



Branchial sac well developed, not folded. Consisting of 



