608 PROP. w. A. heedman's eeyised 



!Tenta<;le3 8, 2 large lateral and 6 small. 

 P. Vallii'^,I.SLh. (Med.) 

 Tentacles 6, 2 large lateral and 4 small. 

 P. Eenieri, Lamt. (Med.) 



Q /Tentacles 8, all one size F.Lamarcki,'S.evA.va. (N.W.Eur.) 



"^ \ Tentacles 16, 8 long and 8 short 5 



r Ascidiozooids yellowish, marked with brown. 

 5 ] P. Jeffreysi, Herdm. (Med.) 



I Ascidiozooids of a bluish colour ... P. Savignyi, Herdm. (N.W. Eur.) 



BoTETLLOiDES, H. MUfie-Edw., 1842. 



Colony thin, incrusting aud usually gelatinous. 

 Systems elliptical or elongated, forming branclied and some- 

 times anastomosing lines. 



Ascidiozooids cylindrical, witli tlie apertures placed near one 

 another on the anterior end. 



Test Boit and gelatinous, never much thickened, penetrated by 

 many vessels. 



Branchial sac long and well developed. 



Alimentary canal placed alongside the branchial sac at its 

 posterior end. 



Gonads placed on both sides of the body near the posterior end. 

 In this case, as in Botryllus, it is useless to attempt to distin- 

 guish the species in brief tabular form in our present vrant of 

 knowledge of the internal structure of so many of them ; conse- 

 quently I give the following list of the known species ; some of 

 them are in a very doubtful condition. 



B. Leachii, Sav. (N.W. Eur., Med.) Purple, with yellow and white 



marks. 

 B. luteum, v. Dr. (Adr.) Green-yellow; tentacles 8, 4 large; ascidio- 

 zooids 3 mm. in length 

 B. purptireum, v. Dr. (Adr.) Tentacles 8, 4 large ; ascidiozooids 3 mm. 

 .B. 6'ascoi, Delia Valle. (Med.) Tentacles 4; ascidiozooids 2 mm. 

 B. Emeryi, Delia Valle. (Med.) Tentacles 8, 4 large. 

 B. rubrum, H. M.-Edw. (N.W. Eur., Med.) Colour yellow to red; 



4 tentacles. 

 B. rosaceiis, Grube. (Med., Eed S.) Purple-red with white lines. 

 B. monowiybrmzs, Delia Valle. (Med.) Yellow-green; tentacles 8, alter- 

 nately larger; ascidiozooids 2 mm. 

 B. albicans, H. M.-Edw. (N.W. Eur., Med.) Pure white. 

 B. ciliatus, D. Ch. (Med.) 

 B. tyreum,Iievdm. (Mai.) 



B. ^erspicmim, Herdm. (Mai.) And var. rubicundum. 

 B. nigrum, Herdm. (Atl.) 



* With se^ eral colour varieties noted by Lahille. 



