MOLGULA OCULATA. 49 



CHANNEL ISLANDS Guernsey (Norman). 

 First record. Forbes, 1848; coll. Forbes and 

 Me Andrew [1846]. 



Professor Edward Forbes compares the apertures of 

 this very singular Molgula to eyes set in a spectacle- 

 frame. Owing to the softness of the test, the animal 

 collapses much in dying, the centre falling in, while 

 the sides are kept out by the stiffening of shelly 

 matter, so that the body assumes something of a 

 saucer-shape. The external fibres are numerous, 

 stout, twisted and angulated, with irregular pointed 

 processes ; they are frequently enlarged at the ex- 

 tremity. 



The mantle (PI. XXIV, figs. 7 and 8) is exceedingly 

 delicate and so firmly adherent to the test that it 

 cannot be removed without laceration ; it is perfectly 

 hyaline. 



The branchial sac (PI. XXIV, fig. 10) has seven 

 folds on each side, the folds have four membranous 

 rods at the sides, and there is usually one a little 

 distance from the base. The spirals are large and 

 irregular, and are centred in the folds, the radiating 

 vessels being numerous and stout, giving to the organ 

 a beautifully-trellised appearance. The branchial 

 tubercle is oval, with the convolutions, which are well 

 developed, turned downwards and backwards. There 

 are 14 or 15 bipinnate tentacular filaments, somewhat 

 irregular in size. 



4. Molgula valvata sp. nov. 

 (PI. XXV, fig. 1 ; and figs. 38 and 39 in text.) 



Bod]/ transversely ovate, slightly compressed, un- 

 attached, thinly covered with minute particles of 

 sand and mud. Apertures a little apart, wide and 

 moderately produced, placed in a narrow depression, 

 with the margins expanded into valvular folds. Test 

 rather delicate, soft, and colourless, covered with 

 numerous, very delicate, angulated fibrils. Mantle 



n. 4 



