1895.] ME. r. E. BEDDARD ON NEW EAKTHWOBMS. iil3 



which is rather limited in extei)t ; in only one species does it 

 occupy more than segments xiii.-xvii. ; in the ^'e\v -Zealand species 

 the cJitellum often extends back to the xixth segment. The 

 American species, too, are never of large size ; a great many of them 

 are very darkly pigmented, a circumstance which is only met with 

 in Acanthodriliis smithii anions; Xew-Zealand Acanthodrili. 



o 



It is interesting that many of these species live equally well in 

 fresh water and on land. Amnthodrilus dcilei, for instance, and 

 Acanthodrilus pictus occurred in Dr. Michaelsen's collection from 

 freshwater gatherings as well as from those in forests. This 

 peculiarity of the genus is not, however, confined to the South- 

 American representatives. The New-Zealand Acanthodrilus 

 pidudosus and the Australian Acanthodrilus schmardie also were 

 collected from freshwater sources. I shall now commence the 

 enumeration of the species collected by Dr. Michaelsen. In the 

 description it will be understood that in all species the nephridia 

 are paired, the dorsal vessel single, the spermathecse in viii., ix., and, 

 of course, the ovaries in xiii. 



(1) Acanthodrilus decipiens, n. sp. 



To a single specimen of Acanthodrilus from near Estancilla, 

 Pi'ovince of Valdivia, I give the name of " decipiens " on account of 

 its strong superficial likeness to a Microscole.r. I had at first 

 passed it over as an example of that genus, which occurs in the 

 same region. This species is one of the smallest of Acanthodrilus ; 

 the measurements were : length ^.5 ram., diameter 2-3 mm. The 

 number of segments of the worm were 110. 



The colour (in alcohol) is of a rich brown above, the setae being 

 implanted within white circles. 



The prostomium is continued over the buccal segment by parallel 

 furrows. The setse are paired, but not so strictly as in Acccntho- 

 drilus dalei, for instance. The implantation of the setae is such as 

 to give to the posterior part of the body a quadrangular aspect. 



The clitellum occupies segments xiii.-xvii. 



Dorsal pores are present. 



Thei'e appear to be small median genital papillae upon segments 

 xvii. and xix., with a larger also median papilla upon xx. 



As there was only a single specimen of the worm, I am 

 not able to give a complete account of the internal structure, which, 

 liowever, shows no specially interesting peculiarities. 



The gizzard is very large and stout, relatively to the size of the 

 worm . 



The spermatheca) have each a single good-sized diverticulum. 



The spermiducal glands extend through two or three segments 

 only ; the penial setge, of which I found seven mature and 

 immature in a single bundle, are of a fair length, but are not 

 ornamented. 



Hah. St. 41, Estancilla, Yaldivia. 



A larger specimen from St. 47 measured 4() mm. 



