38 ASCIDIAD^. 



apertures, having a very thick outer tunic, in which Modiola mar- 

 morata is generally embedded, is not uncommon at CuUercoats, 

 according to Mr. Alder, and is probably the adult of Professor 

 Macgillivray's species. 



4. 0. QUADEANGULARis, E. Forbes. 

 PL D, fig. 1. 



Body conical ; test thick, coriaceous, dark reddish-brown, 

 warty; orifices rather large, on produced conical quadrangular 

 eminences, the angles formed by strong ribs composed of united 

 warts ; rims of orifices white, with a fine crimson bordering line. 

 Length nearly two inches. 



Dredged in Loch Fine, from a depth of thirty fathoms, (1845,) 

 R. M'Andrew and E. P. 



5. 0. iNFORMis, E. Forbes. 



Body rudely conical, subtuberous ; test thick, coriaceous, 

 crimson, covered with rather undefined, oblong, large warts ; ori- 

 fices on conical, obtuse projections, 4:-lobed, deep crimson. 

 Length two inches. 



Dredged in from seven to nine fathoms water in Zetland and in 

 Stromness Bay, Orkneys, J. Goodsir and E. F. (1839.) 



6. C. TEssELLATA, E. Forbes. 



PI. D, fig. 3. 



Body transversely ovate, and shaped not unlike the Psolns sqiia- 

 matus ; test coriaceous, tessellated by regular, smooth, hexagonal, 

 oblong, depressed spaces or warts, each of which is darkly tinted 

 in the centre, so that the creature appears to be tawny, speckled 

 with regular purple spots ; orifices quadrangular, with deep crim- 

 son margins, on rather short and distinct conical eminences, which 

 are more deeply tinted with purple than the body. Length half 

 an inch. 



Dredged, adhering to a stone, in twenty-five fathoms water, 

 Mount's Bay, Cornwall, (1846,) R. M'Andrew and E. F. 



