184 MEGASCOLEX TEMPLETON. 



of MegoM-oiex coeruleus aud could not find any charac- 

 teristic difi'erence between Perichaeta and Megascoiex. 

 His conclusion , that both genera are identical , I believe 

 to be quite exact and consequently the name Perichaeta 

 must be cancelled , while Megascoiex has indisputable claims 

 of priority. We must regret that Perrier ^), who afterwards 

 has so much contributed to our knowledge of the genus Peri- 

 chaeta , not only has fallen into the same error above referred 

 to , but moreover that he imputes Baird from having confused 

 the genus Perichaeta with Megascoiex (Rech. p. s. a I'hist. 

 des Lombr. terr. Nouv. Arch. Mus. Hist. Nat. T. VIU, p. 153). 



We are indebted to, Leon Vaillant (loc. cit.) for ha- 

 ving not only pointed out the great diöerencos between 

 Megascoiex and Lumhricus, but also for having understood 

 that there must be taken account of the internal anato- 

 mical characters , to distinguish the species of these worms, 

 which show so great a conformity in their external appearance. 

 He demonstrated the formation of the girdle by three seg- 

 ments , the situation of the male genital orifices behind 

 the girdle, the absence of true segmental organs, the pre- 

 sence of a gland near the opening of the vasa deferentia 

 and of a pair of coeca on the intestine in the 26th (23th 

 Vaill.) segment. Those observations were afterwards con- 

 firmed and augmented by Perrier; he pointed out that 

 the girdle is constituted by the 14th , 15th and 16th 

 segment , that the male genital orifices are situated on the 

 second ring behind the cingulum (18th segm.) and de- 

 monstrated also the uneven orifice of the oviduct on the 

 ventral side of the first girdle-segment (14th). 



In his ample memoir » Recherches pour servir a I'his- 

 toire des Lombriciens terrestres" Perrier gives a description 

 of six new species, accompanied by many anatomical de- 



1) In his historical review on the Earthworms Ferrier mentiones Perichaeta 

 instead of Meijascolex as one of the genera, classiiied hy Grube in the family 

 of Lumbricina ; this must be a mistake , because the genus Perichaeta was 

 formed 10 years after the publication of //Die Fam. der Anneliden'". 



Notes irom tlie Leyden JMuseuxn , "Vol. V. 



