ASCIDIANS COLLECTED BY THE YACHT ' GLIMPSE,' 1881. 535 



Tentacles rather small and much branclied, very numerous, and 

 of different sizes placed irregularly. 



Dorsal tulercle rather large, but placed in a small perituber- 

 cular area (PL XI. fig. 7). Shape broadly cordate, with both 

 horns turned inwards and the aperture directed posteriorly. 



Alimentary canal on the left side of the branchial sac. (Eso- 

 phageal aperture rather more than halfway down the dorsal edge. 

 Stomach not very distinct (PL XI. fig. 3, st.). Intestine long, its 

 loop being turned anteriorly and then dorsally, so as to enclose 

 the left genital mass and bound it anteriorly. 



Genital glands large, forming transversely elongated yellow 

 masses in the centre of each side (PL XI. figs. 2 and 3, ov.) ; left 

 one in the space between the second part of the intestine and the 

 rectum ; right one anterior to the renal organ, on the right side 

 of the mantle. 



Renal organ elongated transversely, not so large as the right 

 genital mass (PL XI. fig. 2, ren.), containing a number of yel- 

 lowish-brown, irregularly branched, and nodulated concretions 

 (PL XI. fig. 8). 



Locality. Hooles Bay ; 1 fathom ; end of May 1881 : 2 speci- 

 mens. The above description is taken from the larger specimen. 



The only compound Ascidians preserved in the collection were 

 a few colonies of Botryllus scJilosseri, Savigny, and several small 

 colonies of Leptoclinum alhidum, Milne-Edwards, growing over 

 the outer surface of the test of an Ascidia. Both species were 

 from the Orwell, 2-3 fathoms, 



DESCEIPTION OF THE PLATES. 

 Plate X. 



Figs. 1-6. Ascidia mamillata, Cuv., and details. 1. Animal with the test 

 remoTcd, to show the mantle and the relations of the branchial sac 

 and intestine, natural size. 2. Part of circlet of tentacles and papil- 

 lated zona prabranchialis, higlily magnified. 3. Anterior part of dor- 

 sal lamina, sHghtly enlarged. 4. Anterior end of previous figure, 

 more magnified. 5. Optical transverse section of a papilla of the zona 

 prajbranchialis. 



Fig. 6. Polycarpa comata, Alder. Portion of the branchial sac, seen from the 

 inside, magnified. 



Plate XL 



Figs. 1-8. Molgtda ccEpiformis, n. sp., and details of anatomy. 1. Animal, of 

 the natural size, from the right side. 2. The same, with test removed. 

 3. The alimentary canal and left genital mass in their natural posi- 

 tion, slightly enlarged. 4. Portion of branchial sac, seen from the in- 

 side, magnified. 5. Anterior end of eudostyle, to show the relations 



