374 SUPPLEMENTARY NOTES 



near together at the anterior end, while in ours they are widely 

 separated." — Ald. Cat. p. 107. 



A. elliptica, Alder anil Hancock. 



" Body elliptical, a little convex on the upper side, and flat 

 beneath, of a dull and sub-opaque brownish or yellowish white ; 

 attached through its whole length by a rather inconspicuous disc. 

 Branchial aperture not quite terminal, at the anterior end papillose, 

 very little elevated, and divided into eight tubercular segments. 

 Anal aperture situated a little below the branchial one, on the 

 left side, not prominent, with six tubercles. Outer tunic tough, 

 sub-opaque, nearly smooth but rather coarse ; inner tunic opaque 

 white or flesh-coloured, with a few spots of red between the 

 apertures. The red ocelli of the apertures, which are scarcely 

 visible outside, are distinct in the inner tunic. Branchial sac 

 reticulated with slender papilla) at the intersections of the larger 

 meshes. Length, three-quarters of an inch ; breadth, about one- 

 third less. Attached to the under side of stones within tide- 

 marks. Cullercoats. Not common." — Ald. Cat. p. 107. 



A. pellucida, Alder and Hancock. 



" Body depressed, hyaline, subtriangular, attached laterally by 

 a broad disc. Branchial aperture terminal, wide and tubular, 

 divided into eight segments with red ocelli. Anal aperture 

 situated a little below it on the left side, tubular and curved 

 inwards towards the upper surface, with six ocellated segments. 

 Outer tunic smooth, coriaceous, colourless and perfectly trans- 

 parent. Inner tunic not above one-half the size of the outer one, 

 opaque yellowish white, inclined to red on the lower part. Length 

 half an inch. Under stones within tide-marks. Cullercoats, 

 rare." — Ald. Cat. p. 108. 



Molgula arenosa, Alder and Hancock. 



The species of Molgula which we have described and figured as 

 the Ascldia tubularis of the " Zoologia Danica," is considered 

 distinct by Alder and Hancock, who have given it the above 

 very appropriate appellation. 



