Benham. — On a Nctv Species of Earthworm. 273 



Aet. XXIX. — On a Ncic Species of Earthiuorm from Norfolk 



Island. 



By W. Blaxland Benham, Professor of Biology, University 



of Otago. 

 [Read before the Otago Institute, 14th October, 1902.] 

 Plates XXII.-XXVI. 

 Owing to the kindness of Professor Dendy I have been 

 enabled to examine a small collection of earthworms made 

 by Mr. Laing on Norfolk Island. The specimens were in 

 two lots. One lot turns out to consist of introduced Euro- 

 pean worms — Allolobophora caliginosa — a species which seems 

 especially hardy and capable of adapting itself to a great 

 variety of conditions, as it is now extremely widely spread, 

 being met with wherever commercial intercourse with Europe 

 has been established. The second lot consists of a few frag- 

 ments (but, fortunately, two of these were the anterior 

 moieties) of a worm which belongs to the genus Megascolex, 

 the headquarters of which is Australia, though several species 

 occur in Ceylon, and a few elsewhere in the Oriental region. 

 The species does not agree with any hitherto described worms, 

 and I suggest the specific name " laingii " for it. Owing to 

 the poorness of preseiwation several points were not fully 

 followed up, so that certain gaps in our knowledge of its 

 anatomy remain. 



Megascolex laingii, n. sp. 



Colotir, in alcohol, purplish-red, with a darker line round 

 the middle of each segment ; pale below. 



Length of longest fragment 20 mm., by 2 mm. in diameter, 

 containing 28 segments. 



Prostomium broad, its base extending nearly across the 

 peristomium ; its length short ; imbedded about one-third 

 into peristomium. No posterior groove — i.e., "epilobic." 



Chcetce, in mid-body, about 32 — i.e., 16 on each side — with 

 a distinct dorsal and ventral gap, the latter rather the 

 greater. The number gets smaller anteriorly, as does the 

 ventral gap, thus : Total number on 6th segment, 24 ; 3rd seg- 

 ment, 20 ; 2nd segment, 16. The more dorsal chaetae of each 

 ring are further apart than the more ventral ones. 



The clitellum is most unfortunately not yet developed. 



The male pores are on small rounded papillae on the 18th 

 segment, in line with chaeta b (i.e., the second from below) ; 

 each papilla is continuous on its external margin, with a short 

 longitudinal ridge extending across the 18th segment. On the 

 17th segment is a pair of transverse ridges, or oval papillae, 

 18 



