59 



each other in their external appearance, show so marked differences 

 in their internal structure , that some of them , without any doubt must, 

 be regarded as the types of new genera. Rosa already proposed to 

 separate Megascolex from Perichaeta, and Beddard in a recent paper 

 added the new genera Diporochaeta , Anisochaeta and Hoplochaeta. 

 Though his modification must be looked on as a great improvement, 

 I believe nevertheless, that it must be considered as only a provisional 

 attempt to divide this family, for unfortunately the information on 

 the structure of several species is very superficial and incomplete. The 

 genus Perionyx , though presenting large paired nephridia , in my 

 opinion, must not be separated from the Perichaeticlae, as proposed 

 by Benham; perhaps Megascolex armatus, which possesses tufts of 

 nephridial tubules as well as large nephridia , will prove to form a link 

 between the genera plectonephrica and meganephrica. 



Perichaeta Schmarda (s. s.) 

 (Megascolex Baird, Horst). 



Setae numerous, arranged in a continuous row round each segment. 

 Clitellum consisting of three segments XIV— XVI. Gizzard posterior 

 to segment VII. Intestinal coeca in segment XXVI 1 ). 



The confusion of Megascolex and Perichaeta, caused by Schmarda's 

 and Vaillant's misunderstanding of Templeton's original description, 

 and by Baird's inaccurate observations, was cleared up by Beddard, 

 who had the opportunity of examining Templeton's type-specimens. 



9. Perichaeta musica Horst 2 ). 

 Java: Tjibodas. 



Of this huge worm, the largest known Perichaeta-s^ecies , several 

 examples were collected at Tjibodas. 



The largest specimen measures 440 mm. in length; the number 

 of its segments amount to 124. In the description of this worm, in 

 my earlier paper, I omitted to note, that the row of setae is not en- 

 tirely continuous , but that there is a small gap in the dorsal mid-line , 

 equal to the interspaces between 2 or 3 of the neighbouring setae; 



1) According to Beddakd's recent investigations (Proc. Zool. Soc. 1892) in P. tapro- 

 banae the intestinal coeca should be absent. 



2) Notes Leyden Museum, Vol. V, 1883, p. 193; Ibidem, Vol. XII, 1890, p. 236 

 PI. X, fig. 6; A. G. Vorderman, Natuurk. Tijdschr. Ned. Indie, Vol. XLI, 1881, p. 1 

 PL I.; Ibidem, Vol. XLIV, 1884, p. 1. 



