322 RECORDS OF THE AUSTRALIAN' MDSEt'M. 



latter is, strong and elastic. The posterior liver is very large \\itli a 

 furrowed surface. The bile duct leading to the second stomach is free for 

 15 mm. of its length. 



Vdscnlar t^iisfeni. — The heart is contained in a thin Nvalled pericardium, 

 the walls of which ai'e fused with the lung posteriorly. The ventricle is 

 35 mm. in length and the atrium four mm. The aortic valves are con- 

 spicuous, and with the atrio-ventricular valves are crescentic in shape. 

 The blood for at>i"ation is conducted from the sinus venosus by the sinus 

 laterales, and the sinus pediaeus mediauus ; and after aeration is passed 

 to the atrium via the pulmonary veins. 



Nervuiis systoti. — The central nervous ganglia is contained in a capsule 

 of connective tissue, and is situated above the oesophagus; upper and 

 lower divisions are discernible connected by comniisures. The upper or 

 cerebral ganglion gives off the nervus tentacularis to the tentacle, and 

 from this the thin nervus opticus originates. A delicate set is separable 

 into nervi velares, nervi orales, nervi labiales and a distinct nervu« bulbus 

 pharyngens, while a nervus genitalis externus turns sharply downwards 

 to the penis. From the lower ganglion a delicate network includes the 

 origin of the pleural ganglia and the stronger pedal ganglia from which 

 tha pedal branches arise. The buccal ganglion is triangular in shape and 

 is much longer than the neighbouring ganglia, with which it is connected 

 by commisures ; two branches arise to innervate the oesphagus and the 

 salivary glands. 



Bespiratory system. — The lung is large and soft grey in coloui', the 

 outer walls fusing with the inner side of the mantle, and the anterior 

 walls with the pericardium. The inner walls are very spong)^ in texture, 

 and are covered with a thin tissue which is continued into the respiratory 

 tube opening on the lower inner side. 



Excretory system. — Associated with the lung is a small yellowish 

 kidney, with a very narrow urinary chamber. The organ of l^ojanus does 

 not seem to be present. The intestinal system is detailed under the 

 Alimentary system. 



Reprodnctliw, system. — On lifting the visceral mass, the genital mass 

 is seen to occupy about a quarter of the anterior area of the bod}- ; the 

 whole is covered and connected by membrane, which is easily removed 

 with a needle point. The yellowish seminal bladder protiudes well into 

 the mantle cavity, and the hermaphrodite duct is conspicuous by its size, 

 yellowish colour and deep convolutions. It is somewhat spherical in shape 

 and the main ducts — the female leading to the albuminiparons gland 

 and the male to the vas defeiens — are thick and strong. The vas deferens 

 accompanies the vagina, to which it is connected by membrane, as tar as 

 the female genital opening, and from here it goes deeply into the body 

 wall and becomes free again near the opening of the dait gland, continuing 

 from here as a more thickened coil to the penis. The penis is sausage 

 shaped and about four mm. in length ; no appendiculai' gland or cartila- 

 ginous hooks are apparent. 



fllstnlogy. — The histology of the dorsal tubeicles of the ( hicliiih'idn 

 has been adniiiably wojked by Semper, and compared in this species by 

 Tiendenfeld and Teiiison Woods. 



Locality. — Lane Cove Hiver (Port Jackson). 



