188 Memoirs of the Indian Museum. [Vol. VII, 



than to that of modern zoology, and would include several groups without any mod- 

 ern representatives. In any case a general idea of the phylogeny of the genus is as 

 yet unattainable owing to our deficient knowledge of the earlier tertiary faunas of the 

 east. 



It will be noticed that the majority of the living species belong to a single group, 

 which may be distinguished as the group of Pirula reticulata, ancestral forms of which 

 are known as early as the middle eocene of Europe. Pirula investigator is belongs 

 to a group of which the earliest known representative, Pirula concinna, Beyrich, has 

 been observed in the oligocène both of Germany and of Burma ; a second fossil form, 

 Pirula pamotanensis, Martin, occurring in the lower miocène of Java and of Kachh. 

 The ancestry of Pirula ficus is at present quite unknown, and is perhaps of eastern 

 origin. 



With regard to the substitution by Swainson, in 1840, of the name Ficula instead 

 of Pirula under pretext of the want of homogeneousness of Lamarck's genus, it is to 

 be observed that as early as 1823, Sowerby (Genera of Shells) had already circum- 

 scribed Pirula within exactly the same limits as Swainson' s Ficula, giving, as the 

 living type, a figure of a shell which is referred to Pirula reticulata, Lamk., but which 

 really represents P. papyratia, Say, while P. tricarinata, Lamk. and P. burdigalensis, 

 Sow. are figured as examples respectively of the earlier and later fossil forms. 



The following is a list of the specimens in the Indian Museum collections : — 



1. Pirula reticulata, Lamarck. 



Bimlipatam (Wood-Mason), two specimens. 



Hong-Kong, two specimens remarkable for their exceptionally prominent spire. 

 I have carefully examined them and ascertained that they are not, as might be 

 thought, immature specimens of Pirula dussumieri. 



Laccadive sea, Station 248 (8°37 / N., 75°37'3o" E.), at a depth of 224-284 fathoms, 

 in sand. (M -j-). One specimen. 



Malabar coast, 45 fathoms, Marine Survey, 1891-2 (No. 8 - 1 ! r i ), two specimens. 



Maldives, two specimens. 



In Lagoon of Northern Maldive Atoll (Station 148), 15-30 fathoms, in sand, 

 shells, and corals, one specimen. 



Persian Gulf, one specimen. 



Sind, one specimen. 



Vizagapatam, between Dolphin's Nose and Scandal Point (Rev. H. Hosten, 

 S.J.) 18-1 — 17-6-16. One specimen. 



" Indian seas," three specimens of uncertain locality, No. 2588. 



Locality unknown. One fine specimen, No. 2590. 



The species is also known in a fossil condition from the tertiary of Karikal and 

 of Java ; also of Europe. 



2. Pirula papyratia, Say. 

 Florida, four specimens, No. 2597. 



