ASCIDIANS OF THE PHILIPPINES — VAN NAME. 71 



For the reasons rendering necessary shifting of the names Tethyum 

 and Tethyidae see Huntsman, 1912. 



The definition of the family as given by Hartmeyer will need to be 

 made somewhat broader to accommodate the following genus. 



CTENYURA, new genus. 



Differs from Pyura Molina, 1810, in having reproductive organs 

 on the right side only. These consist of small oval masses containing 

 both eggs and testes arranged along a common oviduct (probably 

 accompanied by a common sperm duct) with which they communi- 

 cate by short branches. Along the summit of each fold the wall of 

 the branchial sac is raised to small infundibula upon which the 

 stigmata exhibit a spiral arrangement. This last character is unique 

 in this family with the single exception of the Japanese species 

 Pyura comma (Hartmeyer), 1906, in which the branchial sac is 

 similar to that of the present genus. P. comma, however, has gonads 

 on both sides of the body, as is characteristic of Pyura. 



A branchial sac with infundibula and spiral stigmata closely 

 resembling those of the Molgulidae combined with the general char- 

 acters of the genus Pyura would seem to indicate a connecting form 

 between the families Molgulidae and Tethyidae [Cynthiidae], from 

 which the Molgulidae are in all probability directly descended, and 

 would seem also at first sight to break down much of the distinc- 

 tion between the two families and justify uniting them. There is, 

 however, the possibility that the resemblances in the branchial sac 

 are due to convergence rather than common descent; in support of 

 this it may be urged that neither the present genus nor Hartmeyer's 

 species appear to approach the Molgulidae in their remaining char- 

 acters any more closely than their allies which have no infundibula. 



The name given this genus is, in accordance with its intermediate 

 characters, a compound of parts of the names Ctenicella, a genus of 

 Molgulidae, and Pyura, of the present family. 



Type of the genus. — Ctenyura intermedia, new species. 



CTENYURA INTERMEDIA, new species. 



Plate 32, fig. 42. 



Body of irregularly rounded form, attached by a wide area on the 

 ventral surface, with widely separated, diverging retractile tubes, 

 which, though capable of considerable extension, may not project 

 much beyond the surface when retracted. This is partly owing to 

 the great thickness of the test. Lobes of the apertures not readily 

 counted in the contracted state. Several individuals sometimes ad- 

 here together. Test very thick, semicartilaginous, rather translucent, 

 of a dirty white color; the external surface, which is rough and 



