Here are the two official botanical descriptions for the species in question. Right off the bat you can tell the two plants apart by the number of leaves per growth, the flower stems also show differences with canaliculata's being 2-3.5" tall where as cylindrica's is 2-3' high.

http://nolinoideae.e-monocot.org/taxonomy/term/119

http://nolinoideae.e-monocot.org/taxonomy/term/120

Mike

Penguu, You are right to wonder about the difference between these two sansevierias. However, like many similar looking sansevierias, they are not at all alike when seen up close with your own eyes and felt with your own fingers. I have not looked at the above web pages cited by Mikedahms, but the major differences between these 2 species, especially when not in flower, are in their size and the presence of grooves in the leaves of canaliculata. Canaliculata has solitary leaves that often grow close together on the rhizome. They also have a gentle curve, and clearly have longitudinal grooves; cylindrica leaves are smooth. There is no crossbanding of color (alternating green-gray bands) in their leaves as there is in cylindrica. I have a good picture of canaliculata in flower which I show here.