Note
Seventeen genera, 48 species and 7 varieties of diatoms from the coastal waters of Puerto Rico were observed. These
taxa are in the families Achnanthaceae and Naviculaceae (suborder Raphidineae). Twenty-three represent new records
for Puerto Rico, eleven taxa are new for the Caribbean Sea and one is first reported for the Atlantic Ocean. All of the
species are neritic and most are cosmopolitan. Three new combinations are also presented: Plagiotropis longa, P. pusilla
and P. seriata.