50 REPORT ON THE TUNICATA OF PLYMOUTH. 



(Savigny), Podoclavella (Herdmau)^ Stereoclavella (Herdman), and 

 a new genus, Pycnoclavella. described below. 



I believe tliere is abundant reason for dividing the family 

 Clavelinidfej as regarded by Herdman, into several groups ; 

 Perophora, indeed, was excluded by Giard in 1872 and by von 

 Drasche in 1883, while still more recently Lahille (1890) has empha- 

 sised the diffei'ences between Clavelina and Perophora by placing 

 the former genus in the Distoinidas and the latter in the Ascidiidae. 

 Von Drasche's family Clavelinidae includes Diazona, but although a 

 near relationship between Clavelina and Diazona is generally 

 admitted, it must be remembered that the new forms discovered in 

 recent years have rather emphasised than reduced the gap between 

 the two genera ; I have therefore excluded Diazona from the 

 ClavelinidEe altogether. As above defined, this family includes a 

 number of forms about whose close mutual affinity there can be uo 

 doubt. 



1. Clavelina, Savigny. 



AsciDiA, 0. F. Mailer. Zoologia Dauica, vol. ii, 1788. In part. 



— Bruguiere. Hist. Nat. des Vers, Encycl. Methodique, Paris, 1792, 



p. 141. In part. 



— Turton. Linne's General System of Nature, London, 1802, vol. iv, 



p. 92. In part. 

 Clavelina, Savigny. Memoires sur les Auimaux sans Vertebres, Paris, 1816, 

 He Partie, pp. 87 and 109. In part. 



— Savigny. Tableau systematique des Ascidies, p. 171. In part. 



— Fleming. Molluscous Animals, Edinburgh, 1837, p. 202. In part. 



— M. Edwards. Observations sur les Ascidies des Cotes de la Manchc 



Mem. de I'Acad. des Sci., Paris, xviii, 1842, p. 50. In part. 

 Clavellina, Alder. Cat. Moll, of Northumberland and Durham, Trans. Tyne- 



side Nat. Field Club, 1848, p. 108. 

 Clavelina, Forbes and Hanley. Hist. Brit. Moll., i, 1853, p. 26. 

 Clavellina, Adams. Genera of Recent MoUusea, London, 1858, vol. ii, p. 595. 



In part. 

 Clavelina, Qiard. Recherches sur les Syuascidies, Arch. Zool. Exp., i, 1872, 



p. 613. 



— Serdman. Prelim. Report on Tunicata of " Challenger," Proc. Roy. 



Soc. Edin., x, 1880, p. 717. In part. 



— Herdman. Rep. on Tunicata, "Challenger" Reports, vol. vi, 



pt. xvii, p. 245. In part. 



— M. von Drasche. Die Synascidien der Bucht von Rovigno, Wien, 



1883, p. 8. 



— Cams. Prodromus Faun. Mediterr., Stuttgart, 1890, vol. ii, pt. ii, 



p. 476. 



— Herdman. On the Genus Ecteinascidia and its Relations, with 



Descriptions of two new Species, and a Classification of the 

 Family Clavelinidaj, Trans. Biol. Soc. Liverpool, vol. v, 1890, 

 pp. 160, 161. 



