286 Transactions. — Zoology. 



Plagiochaeta ricardi, n. sp. 



Locality. — Four specimens of this fine worm were obtained 

 by Mr. Eichard Henry on Eesolution Island, at the south- 

 west corner of the South Island. In a note he writes, " A 

 common worm, living Gin. down in peaty soil, mostly on 

 the shady side of a hill. It is a favourite food of the roa 

 (Apteryx haastii), which, when hunting for food, walks slowly, 

 with gentle tread, and its head held as if listening. When the 

 bird gets hold of a worm it breaks the latter up to get rid of 

 the gut." 



Colour (in formalin) dark purplish-brown — in fact, almost 

 purple dorsally. When transferred to alcohol the purple tint 

 becomes sienna-brown. 



Dimensions. — This species is of considerable size and 

 bulk in life. The four specimens are from 180 mm. to 

 290 mm. in length, with a diameter ranging from 10 mm. 

 to 14mm. iu the middle of the body; but this is not the 

 greatest diameter. Of these only two — measuring 260 mm. 

 and 290 mm. — are mature. The former of these two contains 

 173 segments. 



The prostomium is epilobic (half), without a posterior 

 groove. 



The chceke are not in couples, nor in paler spots. There 

 are from fifty-two to sixty -four chaetae in the post-clitellar 

 region, separated into a right and left series by a dorsal 

 and a ventral gap of about thrice the width of an inter- 

 chaetal gap. There is no sensible diminution in number of 

 chastae anteriorly. In the clitellar region the more ventral 

 chaetae, a-d, are further apart than elsewhere. 



The clitelluni occupies segments 14 to 20, and even the 

 21st is slightly glandular. The organ is incomplete ventrally, 

 ceasing at the level of the porophores. 



Genital Pores. — The porophores and "spermatic ridge" 

 are similar to those of P. rossii, but the latter is here less 

 curved. The pores are in line with chaeta c, which is absent, 

 though a and b are present on segments 17, 18, and 19. 

 The oviducal pores are in line with the gap a/b. The sper- 

 mathecal pores are indistinguishable externally. It appears 

 that formol, though excellent as a temporary preservative of 

 colour, causes earthworms to shrink a good deal, and the 

 pores become closed. 



Internal Anatomy. 



The seven septa behind segments 8 to 14 are thick, but 

 especially those of 9 to 13. The septum 14/15, as well 

 as the two following septa, are pouched forwards, so that 

 the cavity of the 17th segment is increased beyond its usual 

 size. 



