REPORT ON THE TUNICATA OF PLYMOUTH. 69 



Family 2.— PEROPHOPJM. 



Body undivided into thorax and abdomen ; viscera on the left side 

 of the branchial sac. 



Test transparent, for the most part thin and membranous, rarely 

 traversed by a few sterile stolonial tubes ; never investing the 

 stolons in a common basal sheath; apertures generally well apart, 

 the brauchial terminal and the cloacal dorsal, lobed, or rarely proxi- 

 mate, terminal and only indistinctly lobed. 



Musculature consisting almost exclusively of transverse fibres ; 

 longitudinal fibres rarely present except around the apertures. 



Branchial sac not folded, horizontal membranes absent or feebly 

 developed, replaced or surmounted by interserial rows of papillse ; 

 papillae simple and unbranched or supporting incomplete or complete 

 internal longitudinal bars ; bars papillate or not papillate ; dorsal 

 lamina a longitudinal membrane or represented by a series of slender 

 languettes ; languettes rarely compressed from before backwards ; 

 stigmata straight. 



Tentacles simple, filiform. 



Genitalia in the loop of the intestine ; oviduct and vas deferens 

 present. 



Reproduction by gemmation as well as from ova. 



This family includes the genera Perophora (Wiegmann), Pero- 

 phoropsis (Lahille), Sluiteria (E. van Beneden), and JEcteinascidia 

 (Herdman, sens, strict.). In a complete system of classification it 

 should be placed very near to Eoule's group " Phallusidees," which 

 embraces the genera Ascidiella, Ascidia, and Phallusia. 



A species of Bcteinascidia (E. Moorei), quite recently described by 

 Herdman, appears from his figures to possess dorsal languettes 

 flattened antero-posteriorly, and this is implied, though not directly 

 stated, in the text of his paper. This condition of the languettes is 

 unique within the family, and affords an approach towards the genera 

 Bhopalopsis, Bhopalcea, &c. 



3. Perophora, Wiegmann. 



Ascidia, Lister. Some Observations on tbe Structure and Functions 

 of Tubular and Cellular Polypi and of Ascidffi, Phil. 

 Trans., pt. ii, 1834, pp. 378—382. 



