CLASSIFICATION OF THE TUIS'ICATA. 603 



Test tbin, membranous, transparent. 



Sranchial sac with no internal longitudinal bars and no con- 

 necting-ducts. Numerous (15 or 16) rows of stigmata are 

 present. 



Dorsal lamina represented by languets. 



Alimentary canal on the left side of the branchial sac. 



Gonads forming a network over the intestinal loop. 



This genus contains the single species PeropTioropsis JELerdmani., 

 Lahille, from Banyuls (Med.). 



PoDOCLAVELLA, Kerdman, 1890. 



'Body extremely long and narrow, divided into thorax, abdomen, 

 and a well-marked post-abdominal peduncle. 



Test moderately thick, cartilaginous. 



Brancliial sac with no internal longitudinal bars, and no papilli- 

 form connecting-ducts. 



Viscera extending behind the branchial sac to form a large 

 abdomen. 



I have formed this new genus for the reception of Savigny's 

 Clavelina horealis, and a new species which will be described in 

 the Catalogue of Tunicata of the Australian Museum which I am 

 now preparing. 



Colour light bluish green, tentacles in 2 rows. P. horealis, Sav. (Aret.) 



Colour purplish, tentacles in 1 row P. meridionalis, Herdm. (Austr.) 



SteiieocI/AYELLA*, Herdonan, 1890. 



Body elongated ; attached to a basal mass of solid test which is 

 formed by the fusion or thickening of the stolons ; divided into 

 thorax and abdomen ; apertures circular, not lobed. 



Test thin anteriorly, may be thick and cartilaginous posteriorly 

 where it joins and forms the stolonial mass. 



Branchial sac, &c., as in Clavelina. 



I have grouped together under this name those species of Clave- 

 lina which have the stolons and the posterior ends of the bodies 

 imbedded in a basal mass of test. It may be regarded, along with 

 JPodoclavella, as being scarcely worthy of generic rank, and I am 



* Since this was put in type Garstang has published (May 1891) a description 

 of a new genus, Pycnoclavella, which seems very closely allied to Stereoclavella.- 

 However, it may be a distinct form characterized by the presence of stolonial 

 tubes (vessels) in the free test covering the oesophageal region of the body. It 

 contains the species P. aurilucens, Garst., found at Plymouth. 



