SCYLL^A. 



The intestine is somewhat longer and wider than the oesophagus, and is not much less in 

 diameter than the stomach. 



The liver holds the same central position as in Doris and Tritonia, and consists of six 

 or seven globular balls, seated on the ducts that empty themselves by three very large orifices 

 into the stomach just at the termination of the oesophagus. These glandular balls are made 

 up of convoluted tubes, regularly arranged in two concentric layers : the outer one has the 

 tubes small, frequently folded upon themselves, and placed in a radiating manner. The inner 

 layer, which is twice as thick as the outer one, has a like arrangement of the tubes, but they 

 are not so often folded upon themselves, and are much stouter ; they are joined at the outer 

 extremities with the tubes of the external layer, and, uniting in pairs at their inner termina- 

 tions, give off fine transparent ducts, which, passing towards the centre of the ball, unite to 

 form a large central channel, which leads out of the gland and joins one of the ducts above 

 mentioned as emptying themselves into the stomach. Upon the peripheries of these balls, 

 several small tubes ramify in various directions : they appear to come from the convoluted 

 tubes of the gland, and, uniting, go to form a set of canals which lie loosely among the viscera, 

 and between the viscera and the skin ; and ramifying over the latter, the principal of them 

 pass into the dorsal lobes, and penetrate the branchial tufts. Six or seven minute branches 

 belonging to the same set of canals, are attached nearly in a straight line along the anterior 

 border of the intestine, just below the stomach, and apparently enter that tube. All these 

 tubes and canals are opake, and of a yellowish colour like the gland itself; and when examined 

 with the microscope, are found to contain the same glandular substance. 



The circulatory system is provided with a strong muscular ventricle, placed a little in 

 advance of the middle of the body, immediately below the dorsal skin. The auricle is united 

 to its posterior extremity, and, as in Tritonia Hombergii, is a broad transverse belt receiving- 

 branches on each side from the skin. The aorta, as usual, passes from the anterior apex of 

 the ventricle, and divides into arteries for the supply of the viscera. 



The nervous system is disposed much in the usual manner. The two central oesophageal 

 ganglia are large, elliptical, and slightly constricted in the middle ; the lateral ganglia are 

 much smaller than the central ones, and are nearly circular. The eyes are placed near to 

 the junction of the central with the lateral ganglia. 



The generative organs resemble those of Eolis. The ovary, however, is described by 

 Cuvier to resemble one of the liver masses, and to be placed with them in the abdominal 

 cavity towards the right side. This we failed to detect in the specimen on which our obser- 

 vations were made, as well as the several accessory parts. 



EXPLANATION OF THE PLATES. 



Fig. 1. General view of the viscera of Scylltea pelagica : — a, buccal mass ; b, oesophagus ; c, folliculated 

 gland surrounding the oesophagus, supposed salivary ; d, stomach ; e, intestine ; f, anal 

 nipple ; g, g, g, liver masses ; h, h, h, h, h, branches and tubes passing from the liver masses 

 to the skin and branchial tufts ; i, ventricle of the heart ; j, auricle ; k, cerebral ganglia, 

 with nerves passing from the same ; /, I, I, l } dorsal lobes, exhibiting branchial tufts ; m, 

 retracted penis ; n, convolutions of the testicle. 

 2. Side view of the buccal mass : — a, channel of the mouth ; b, a portion of the corneous jaw, 

 uncovered by the muscle ; c, oesophagus ; d, follicular gland surrounding the oesophagus. 



