214 Mr. F. E. Beddard on 
Megascolex affinis, K. P. 
Pericheta affinis, E. Perrier, Arch. du Muséum, t. viii. p. 106. 7 
I venture to alter Perrier’s name into Megascolex affinis, 
since Dr. Horst * has recently called attention to the identity 
of Templeton’s genus Megascolex + with that subsequently 
termed Pertcheta by Schmarda {. The name Pericheta was 
apparently introduced by Schmarda owing to a misunder- 
standing of empleton’s definition of the genus Megascolex, 
for which he is indeed hardly to be blamed. The defini- 
tion given by Templeton is very imperfect, and seems 
also to be inaccurate, since Baird §, who examined the type 
specimen of Megascolex cwruleus, was unable to find any dif- 
ference between it and Schmarda’s genus Pericheta. Judg- 
ing from T'empleton’s description, Megascolex is very different 
indeed from Pericheta; he states, for example, that the gene- 
rative organs are developed in segments 16, 17, and 18. 
Schmarda evidently considers that this description refers to 
the clitellum; but in any case the description is entirely 
unlike Pericheta, in which genus the testes are nearly always 
in segments 11 and 12; and the 18th segment, upon which 
the vasa deferentia open, never forms part of the clitellum. 
However, since Baird has stated that Megascolex and Pert- 
chetu are identical, Horst is clearly right in wishing to retain 
the name J%egascolex, which has a priority of fifteen years. 
It might perhaps be advisable to limit the name Megascolea 
to those worms which are characterized by (1) the presence of 
a continuous ring of setee upon the segments of the body, (2) 
the possession of a clitellum occupying segments 14-16 in- 
clusive, (3) the position of the two male generative apertures 
behind the clitellum upon the 18th segment and of the single 
female aperture upon the 14th segment within the clitellum ; 
while the name Lericheta might be applied to certain other 
forms which present a fundamental resemblance to the above- 
mentioned group, but differ in one or both ot the following 
characters :—(1) in the ring of setee upon each segment being 
discontinuous at one or more points; (2) in the clitellum occu- 
pying more or fewer segments of the body than three. 
In this way several species recently described by Perrier || 
from the Philippine Islands, such as, for example, Pertcheta 
* Horst, Notes from the Leyden Museum, vol. y. p. 183, 
+ Templeton, Proc. Zool. Soc. 1844. 
{ Schmarda, Neue wirbellose Thiere, 1861, Bd. 1. ii. p. 13. 
§ Baird, Proc. Zool. Soc. 1869, p. 40. 
|| Perrier, Comptes Rendus, t. [xxxi. p. 1043. 
