CLASSIFICATION OF THE TUNICATA. 623 



2 fAtrial languet trilobed 5 



\ Atrial languet simple 6 



r Transparent, with orange pigment on anter.ior end of endostyle. 

 5 j A.pu7icht,m*, Giard. (N.W. Eur.) 



[ White colour A. albicans, M.-Edw. (N.W.Eur.) 



P / Colony sandy 7 



\ Colony not sandy 8 



n / Few folds, 5, in stomach-wall A. subacutum, v. Dr. (Med.) 



[ Many folds, 10 or more 9 



q f Of a dark-brown colour A.fuscum,Y.J)v. (Med.) 



[Ot a light colour 10 



1Q / Of a greyish-yellow tint, much sand . A. densum, Giard. (N.W. Eur.) 



I Of a light-brown tint, little sand A. commune, v. Dr. (Med.) 



Q f Colony on a short peduncle 11 



I Not pedunculated 12 



,, I Colour black A. 'iiigrum,'S.evdiTa. (A. Arct.) 



[ Colour not black 13 



-. q r Stigmata small, short, and inconspicuous 14 



I Stigmata moderately long 15 



-.^/Stomach spherical A. gJobosum, Herdm. (A. Arct.) 



I Stomach cylindrical A. variabile,'S.Q¥Am. (A. Arct.) 



f Colony grey, with yellowish ascidiozooids. 



15 -^ A. colelloides, Herdm. (S. Atl.) 



[ Whole colony of a reddish tint 16 



r Of an orange-red A. proliferuvi, M.-Edw. (N.W. 



16 \ [Eur., Med.) 

 [ Of a pale rose-red ^. tosotwj, D. Valle. (Med.) 



1 Q r Colour white A. albidum,lS.eYAm.. (Austr.) 



" \ Colour not white 17 



,„ [Ascidiozooids very small, less than 5 mm. long 18 



[Ascidiozooids not small, more than 5 mm. long 19 



, Q r Stigmata well developed A. /cevigahcm, ILerdm. (Mag.) 



\ Stigmata small 20 



f,p. r Colony pale liver-coloured, opaque... A. hepaticum, Herdm. (?) 



I Colony light grey, transparent A. recumbens, 'BLQvA.m.. (Mag.) 



,q /Atrial languet long A. irregulare, Herdm. (Mag.) 



[ Atrial languet short and inconspicuous 21 



{Numerous stigmata in branchial sac, 18-20 rows. 

 A. torquatum, v. Dr. (Med.) 

 Comparatively few stigmata, few rows 22 



nn /Intestinal loop long and nai-row A.compla'natii'm,'KevdLva.{K.Ajcct.) 



\ Intestinal loop short A. pallidulum, Herdm. (Mag.) 



Atopogaster, Herdman. 1885. 



Colony massive and usually of large size. 



Systems simple or inconspicuou?. 



Ascidiozooids large or small, always mucli elongated antero- 

 posteriorly. Branchial aperture 6-lobed. 



Test thick, and usually cartilaginous and tough ; not incrusted 

 with sand. 



* The MorcheUiojosis Fleyberianns of LahiUe. 



