Polycitor (Eudistomd) Mayer i nov. sp., from the Tortugas. 93 



mudas, but all these species have four rows of stigmata in the branchial 

 sac and are in many other respects quite different from our species. 



DESCRIPTION OF PLATE. 



a, atrial aperture; fp, fecal pellets; s, stomach; 



b, branchial aperture; i, intestine; t, testes; 



e, endostyle; oe, oesophagus; vd, vas deferens. 

 ep, ectodermal processes; r, rectum; 



1. Largest colony of the collection; natural size. 



2. Ascidiozooid, from the right side; magnified (ca. i6X). 



3. Part of abdomen of another ascidiozooid, very little contracted; magnified 



(ca. 10 X). 



4. Part of abdomen of an ascidiozooid, with stomach situated dorsally; magnified. 



5. Posterior end of the abdomen of an ascidiozooid with two ectodermal processes; 



magnified. 



6. Posterior end of abdomen of an ascidiozooid with fully developed testes; mag- 



nified. 



