BULL^EA. 287 



margins sinuatecl. The body of this animal is therefore com- 

 posed of an upper or head-lobe and the pedal disk ; which, 

 though their continuity is invaded as regards the integuments, 

 are really integral plates from one extremity to the other. 

 The lobes, as in Bulla hydatis, are separated by a deep canal, 

 which, except for a very small extent, makes the circuit of the 

 animal, less profound on the left than on the right side, from 

 whence all the organs that are apparent without dissection 

 may be observed ; as the orifice of the verge on the right 

 side of the head- lobe, the canal which is probably the vas 

 deferens, or a continuation of it, the common receptacle of 

 generation, the points of the branchiae, and the lateral leaflets 

 on each side the mouth. To describe these organs would 

 nearly be a repetition of the notes on Bulla hydatis; as 

 they are essentially the same, the variations need only be 

 mentioned. 



The branchiae, the common receptacle of the ova, &c., are 

 placed more posteriorly here than in that genus. The leaflets 

 around the mouth between the groove, which I take to be 

 salivary glands, are, as to general shape and position, similar 

 to those in B. hydatis; their structure only differs, being 

 composed of close-set, light brown vertical filaments or lines, 

 the extent of which in depth is defined by the width of the 

 canal, instead of being branched. The mouth is at the 

 centre of the anterior part of the canal between the two lobes 

 which assimilate in form about the buccal range, the pedal 

 one more posteriorly expanding into fins or lateral lobular 

 reflections ; the fissure of the mouth is vertical. 



As to the internal organs of the present species, they are 

 nearly identical with those of B. hydatis; the specialties are 

 of the most trifling value ; the ovary and serpentine oviduct, 

 testis, the anus, the heart, auricle, vesica, coarse brown bran- 

 chise, liver and intestine, scarcely offer appreciable variations. 

 The mouth, as in B. hydatis, is armed with a delicate folding 

 masticatory apparatus, consisting in each jaw of about 12-15 

 light-coloured, arched, pointed hooks curving inwards, sup- 

 ported by a fleshy buccal mass, which terminates behind in a 

 very short unarmed lingual riband. 



