THE ANATO.MV OK M i:(; A l.ATK.VCl'US — KKSrKVKV. It? 



the differences itemised under the last a better diHV-i-(,'iiliation 

 of the left cerebral gaIl^di()Il, not only from the sub-intestinal 

 ganglion, but also from its own cerebral and pedal connnissures. 



In the character that this H3'steni diffei\s froDi the four 

 mentioned above, viz., the increase in length of the cerebro-buccal 

 connnissures, it seems to agree with that of Mplotujeaa ( '■'■ Pyriila" ) 

 tuba, Lamk. Souleyet* has iigureil and describerl two long 

 nerves, arising from the cerel)ral ganglion and terminating under 

 the buccal mass, which may l)e justly regarded as cerebro-buccal 

 commissures. Unfortunately, as noted by Bouvier.f 8ouleyet's 

 figure of the centre of the nervous system of M. tuba i.s " very 

 difficult to interpret," so that one cannot compare the rest of the 

 two systems. 



With the first two of the above four nervous systems, I might 

 have bracketed those of FiJgar perversum, Linn., and Chrysodo- 

 mus contraria, Linn., as described and figured by Fischer and 

 Bouvier,! were it not that they are of sinistral mollusca, and 

 therefore turned left for right. 



From what is known of the reproductive systems of Meyala- 

 tr actus, they resemble those of Melongena ("Pyrula" ) tuba, Lamk., 

 as described by 8oule3'et, in essential characters; an unimportant 

 difference is found in the absence from Souleyet's example, of the 

 coiling of the vas-deferens on the surface of the digestive gland. 



"The plan of construction of this ovisac (that of M. aruanii^s) 

 somewhat corresponds to that of Pirula ( S ijcotyjnis ) cancdiculata, 

 Linn., figured by Fischer."§ (Hedley.||) 



VI.— THE SYSTEMATIC ALLOCATION OF THE GENUS. 



Throughout the last section of this paper it will have been 

 noticed that the various organs and S3^stems of organs have been 

 more satisfactoril}' compared with those of Melongena than those 

 of other genera. This repeated resemblance will have forestalled 

 the present section, for it has become obvious as the concluding 

 portion of the section was reached that Megalatractus is closely 

 allied to Melongena, or Semifusus: it therefore occupies a position 

 in the family Turbinellidas, Fischer. 11 



This conclusion is another testimonial to the wonderful abilitv' 

 of Dr. Paul Fischer to seize upon the salient points of a shell 



* Souleyet— Zool. "Bonite," iii., 1S52, p. 618, Atlas, pi. 43, f. 8 and 9. 

 t Bouvier— Ann. Sci. Nat. (7), iii. 1887, p. 25-i. 



X Fischer and Bouvier— Journ. de Conch., (3), xsxii., 1892, p. 150, pis. 

 i. and ii. 

 § Fischer— Man. Conch., 1887, p. 92. 



II Hedley— Proc. Linn. Soe. N.S. Wales, xxv., 1900, p. 508. 

 IT Fischer— Man. Conch., 1887, pp. 618-623. 



