CLASSIFICATION OF THE TUNICATA. 583 



masses (" polycarps ") scattered over the inner surface of the 

 mantle. 



The known species o^ JPolycarpa * may be arranged thus: — 



f Branchial sac with folds rudimentary 1 



\ Branchial sac with folds well developed 2 



fTest very thin, 2 bars on each fold, 6-8 stigaiata. 

 P. mmiita, Herdm. (A. Arct.) 

 Test thick, bars on fold numerous, 1-4 stigmata. 

 P. quadmta, Herdm. (Mai.) 



2 /Less than 4 folds on each side 



\ At least 4 folds on each side 4. 



g / With 2 folds on each side P. simplex, n. sp. (Austr.) [Med.) 



I With 3 on right side and 2 on left. P. glomerata, Aid. (N.W.Eur., 



A r With 5 folds on right side and 4 on left 5 



I With 4 folds on each side 6 



(Test thick ; one horn of dorsal tubercle turned out. 

 P. spongiabilis, Traust. (W. Ind.) 

 Test thin, pellucid ; both horns of dorsal tubercle turned in. 

 P. obteda, Traust. (W. Ind.) 



„ r Branchial sac papillated on inner surface 7 



\ No papillae on interior of branchial sac, 8 



(Tentacles 25, stigmata normal ... P.papUlata,Si\xit. (Mai.) 

 Tentacles 40, stigmata small round apertures. 

 P. Herdmani, Sluifc. (Mai.) 



Q ("Body pedunculated 9 



[Body sessile 10 



q f Individuals aggregated in masses. P. nigricans. Heller. (Ind. O.) 



[ Individuals not aggregated 11 



5-12 stigmata in a mesh 12 



13 or 14 stigmata in a mesh P. spiralis, Sluit. (Mai.) 



■H", r Peduncle almost as long as body 13 



[ Peduncle much shorter than body 14 



{Apertures conspicuous, branchial anterior, atrial dorsal, lobes distinct. 

 P. pedata, Herdm. (Mai.) 

 Apertures inconspicuous, both anterior, lobes indistinct. 

 P. radicata, Herdm. (Austr.) 



1^ /More than 65 tentacles P. viridis,^evA.va. (Austr.) 



[ Fewer than 50 tentacles 15 



f Body roundish, attached posteriorly by branching roots, some adhering 



15 s sand P. pedunc2dafa, HeWer. (Austr.) 



[ Body longish, no adhering roots, surface almost smooth 16 



f Mantle thin, muscles weak, dorsal lamina wide, anterior part sinuous. 

 P. oligocarpa, Sluit. (Mai.) 

 Mantle thick, muscles strong, dorsal lamina smooth and straight. 

 P. data, Heller. (Austr. & Mai.) 



, ^ / Body all covered with sand 17 



[ Body not sandy, or only partially covered 18 



r 4-6 bars on a fold, 1 or 2 in the interspace. 



17 \ P. pusilla, Herdm. (N.W. Eur.) 



I 6-9 bars on a fold, 6-8 in the interspace 19 



* Styela psoloessa, S. aurita, S. argentafa, and S. oUtoria, recently described 

 by Sluiter from the Malay Archipelago, too late for insertion in the table, fall 

 into this genus according to my definitions. 



LINN. JOUitN. — ZOOLOaY, VOL. XXIII. 42 



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