PIIVLOGENY OF FUSUS AND ITS ALLIES. 2/ 



has, liowever, the i^cncral aspect of a F. coins, being larger than 

 the average F. torciniiiis. The specimen furthermore suggests hav- 

 ing been derived from a F. col us rather than F. torcimnis, and that 

 therefore it is retarded in development and not primitive. This can 

 perhaps not be proven, but as stated the whole appearance of the shell 

 suggests it. 



It will thus be seen that a young F. coins or a retarded one have 

 the characteristics of an adult F. toreiimus, and that though a young 

 individual may perhaps be placed under its proper species, the position 

 of a retarded individual must be determined by the standard of indi- 

 vidual opinion. 



Another individual (M. Z. 904 not figured) shows the same re- 

 tarded characteristics. In this, the first seven or eight whorls are in the 

 turricuhis stage, intercalated spirals appearing in the last two of these. 

 The next whorl is transitional, and the two following are typical tuber- 

 culated torcnmus whorls. The last whorl has the tubercles less com- 

 pressed vertically; these therefore have a more rounded or knobbed 

 appearance. This gives them a resemblance to those of a normal F. 

 tuberosus, which, however, belongs to a distinct series. 



This individual is certainly not a typical F. coins, neither can it 

 be classed with typical F. toreumus. It is better classed as a retarded 

 and abnormal variety of the former. 



A specimen from Amboyna (B. S. 6078 not figured) has eight 

 tnrricnlns whorls, four torcmnns whorls and one coins whorl, this 

 latter towards the end merging into a keelless longicandus stage. The 

 number of angular torcni)ins whorls is sometimes as high as six. It is 

 not uncommon for the angular tubercled whorls to extend nearly to 

 the end, the coins stage being restricted to a portion of the last whorl. 

 Such shells, though similar to. are yet distinguishable from gerontic 

 individuals of F. torcnmus. In all these varieties the inner lip is 

 always more or less strongly lirate. 



The following stages then, may be distinguished in typical Fusus 

 coins: 



Protoconch a, smooth. 



b, ribbed. 



Nepionic tnrricnlns stage. 



Neanic torcnmus stage. 



Ephcbic coins stage. 



Gerontic or paraephcbic in accelerated individuals, .longicandus stage. 



Localities: East Indies (M. C. Z. 936, 904?, B. S. 219) ; Philippines 

 (M. C. Z. 902) ; Indian Ocean (M. C. Z. 32) ; Amboyna: Maluccas, 

 (B. S. 6078) ; Ceylon (Reeve). 



