ON PERICHAETIDAE. 203 



Prostata large , occupying segments XVI — XIX, flat, reni- 

 form , with U-shaped duct. Intestinal coeca not present 

 in segment XXVI. 



The two specimens examined by Beddard and first iden- 

 tified by himself with P. hiserialis , afterwards were des- 

 cribed as belonging to a new species, on account of the 

 absence of spermathecae; however, I cannot agree with his 

 assertion , as will appear from the following. 



Perrier, who in 1875 first described P. hiserialis from 

 the Philippines, already pointed out the variability of the 

 number of copulatory papillae in this species; he says »ou 

 peut en effet constituer une série d'individus presentant, 

 en arrière des orifices males , de chaque cote de la ligne 

 médiane veutrale , une rangée de trois, quatre , cinq, six 

 ou sept papilles. Quelques iudividus ont même trois , quatre 

 ou cinq papilles d'un cote, quatre, cinq ou six papilles 

 de I'autre." In 1890 Beddard examined two specimens 

 from Manilla, both characterized by the presence of 5 

 pairs of copulatory papillae. In the foregoing year Michaelsen 

 published a detailed description of the same species , based on 

 the examination of five individuals, collected in Madagascar. 

 He confirmed the variability of the number of copulatory 

 papillae , for of these specimens four showed but 3 pairs 

 of papillae , while the fifth one had 5 pairs of them. 



My own observations about the worms from Surinam are 

 quite in agreement herewith. Eight mature worms came 

 under examination and of these two have 4 pairs of 

 copulatory papillae on segments XIX — XXII ; three of 

 them show only 8 pairs on segments XIX — XXI; one 

 specimen has 3 papillae on segments XIX — XXI at the 

 right side, and on segments XX — XXII at the left, while 

 on both remaining worms one has only 3 papillae at the 

 right, the other one at the left side of the body on 

 segments XIX — XXI. None of them thus showed the 

 number of 5 pairs of papillae , as observed by the above- 

 named naturalists. 



In our specimens, however, the variability is not 



ZVotes from ttie Leyden Museutn, Vol. XX. 



