II. — ZOOLOGY. 



Art. X. — On the New Zealand Lamprey. 



By Arthur Dendy, D.Sc, Professor of Biology in the 

 Canterbury College ; and Margaret F. Olliver, M.A. 



[Rend before the Philosophical Institute of Canterbury, 6th November, 



1901.] 



The lamprey has been found in New Zealand in three well- 

 marked stages of growth — the Ammoccetes, the larval form, 

 very similar to the corresponding stage in the European lam- 

 prey ; the adult Geotria, with a well-developed gular pouch ; 

 and the Velasia, a form intermediate between the other two, 

 with no gular pouch. Little is known of its life-history or 

 habits ; but in October the Velasia come up some of the 

 rivers in shoals, and are caught by the Maoris for food, and 

 the Maoris say that they come down again in December 

 with gular pouches. Very few specimens of any stage have 

 hitherto been preserved, but recently a large number of 

 Velasia were sent to us alive from the Mataura Eiver, up 

 which they were making their annual migration, and as 

 regards this stage we were able to work from the fresh 

 material. 



Both the Velasia stage and the adult Geotria were first 

 described by Gray in 1851, and were classified by him as 

 distinct genera (Geotria and Velasia) of the family Petromy- 

 zomdce. Giinther, in 1870, ranks the two forms as separate 

 species of the genus Geotria; the pouched form he calls 

 Geotria australis, and the Velasia he calls Geotria chilensis, 

 since Geotria in the Velasia stage was first discovered in 

 Chili. Recently Ogilby, in reclassifying the Australian lam- 

 preys, reverts to Gray's system of classification, and places 

 the two forms in different genera. 



Before minutely examining the animals themselves it had 

 occurred to us that possibly, since the larval Ammocoetes was 

 formerly regarded as a separate genus, a similar mistake had 

 been made in the case of the Velasia, which might be only an 

 intermediate form (since it was only found in New Zealand, 

 Australia, and Chili, where the Geotria was also found), and 

 that, if Velasia and Geotria actually were distinct species, it 



