214 MB. r. E. BEUJDARD 0>' NEW EAETHWOKMS. [Mai". 19, 



(2) Acanthodrilus occidentalis, n. sp. 



In point of size this is the most conspicuous o£ all Soutli- 

 Aiuerican species of Acanthodrilus; about a dozen specimens in 

 all were collected by Dr. Michaelsen, and the largest of these 

 slightly exceeds in bulk the largest example of Acantlwdrilus jnetus, 

 Avhich is its only rival in size. 



The present species, however, differs from AcanfJiodrilus pictus in 

 being entirely without integumental pigment, a fact which gives to 

 it in the preserved condition a pale dirty brown colour. The 

 worms are A^ery soft to the touch and the segments are very much 

 annulated. The general appearance, indeed, is like that of the Xew- 

 Zealand species Odocfuptus multiporus ; it is very different from 

 that of any South-American species of the genus which I have had 

 the opportunity of examining. The structure, however, does not 

 in any way resemble that of OctocJuetus ; Acanthodrilus occidentalis 

 is a perfectly tyjjical Acanthodrilus, though differing in detail from 

 any other species known. 



The largest individual at my disposal measured 192 mm.; its 

 diameter was at the widest point 9 mm. The number of segments 

 of this specimen was 365. The colour of the species after death 

 has been already referred to ; during life the colour was (according 

 to Michaelsen) " blau gran ; Kopfende zart rosa." 



The clitellum during life a^ as hardly visible : I could not detect 

 its limits in the preserved specimens. The obscurity of the 

 clitellum gave the worm a certain resemblance to many (xeosco- 

 licids. 



The soft feel of the body is due to the minuteness of the strictly 

 paired setae ; the setae are implanted upon the ventral side of the 

 body ; the ventral area within the setae is to the dorsal area as 

 7 : 11. On the anterior segments of the body I could not detect 

 the setae at all. 



The prostomium is continued by grooves over the buccal segment. 



The dorsal pores commence at the eleventh or twelfth segment. 



The internal anatomj' shows no characters of very great import- 

 ance 



Some of the anterior septa are thickened ; this is the case with 

 the six which immediately follow the gizzard. 



The gizzard, in spite of its large size, is entirely contained between 

 the septa which bound the sixrh segment. There are no distinct 

 calcil'erous glands ; but the oesophagus is red and vascular pos- 

 teriorly. The intestine begins in segment xvii. ; it has a very 

 rudimentary typhlosole. 



The last pair of hearts is in segment xiii. 



The reproductive organs are hke those of other species of the 

 genus. 



There are two pairs of testes in x., xi. ; these gonads are very 

 much frayed out and extend right across their segments, looking as 

 if they were attached to both w alls. 



The sperm-sacs are of fair size ; they are racemose in form and 

 are attached to the front walls of segments xi., xii. 



