1885.] NEW-ZEALAND EARTHWORMS. 811 



these specimens in some detail, and venture to offer to the Society 

 an account of their structure which will, I hope, help to fill up a 

 gap in our knowledge of the anatomy of Earthworms ; at present, 

 beyond a few short descriptions of some six species of this genus, the 

 anatomy of Acanthodrilus is entirely unknown. 1 have endeavoured 

 in the present communication to treat of the structure of this genus 

 in as thorough a fashion as possible, and have taken as my models the 

 excellent memoirs of M. Perrier on Urochieta} and Fontodrilus^ . The 

 anatomy of all three species will be dealt with together, and will form 

 the second part of this paper ; the first part contains some remarks 

 upon the genus and a brief description of three new species. 



Part I. 



The genus Acanthodrilus was instituted by iNI. Perrier in his 

 ' Recherches pour servir a I'histoire des Lombriciens terrestres.'^ 

 It belongs to his group " Postclitelliens,'" inasmuch as the male 

 generative openings are situated behind the clitellum. Tlie structural 

 characters which serve to distinguish this genus from others are: — The 

 presence of four male generative openings, each of which is furnished 

 with a bundle of long, peculiarly modified penial setse, enclosed in a 

 special muscular sac, the ends projecting through the apertures : 

 there is furtliermore a prostate gland in connection with each of 

 these apertures ; the vasa deferentia remain distinct from each other, 

 and pass down the body from their anterior funnel-shaped internal 

 apertures to their external apertures as four distinct tubes. The 

 setse are disposed in pairs as in Lumbricus. 



M. Perrier described three species — A. obtusus and A. ungulalus 

 from New Caledonia, and A. verticiUatus from JNIadagascar. A 

 fourth species of this genus was collected in Kerguelen during 

 the 'I'ransit-of-Venus Expedition, and described by Prof. Lankester* 

 under the name of -4. keryuelenensis. More recently Dr. Horst has 

 recorded the structural characters of two large species from -Liberia, 

 which he has named respectively A. h'ultikoferi and A. schlegelii\ 

 Finally, I have myself described a seventh species from the Cape 

 of Good Hope, under the name of A. capensis^. I shall take the 

 opportunity presently of making some remarks upon the structural 

 ciiaracters of these in connection with the new species to be recorded 

 in the present paper. 



Little or nothing is known about the New- Zealand Earthworms ; 

 pnd, so far as I am aware, there is no anatomical description of 

 any one of the species, some seven in number, which have been 

 recorded by Baird and Hutton^ from this locality. 



Captain Hutton, C.M.Z.S., has briefly described four species of 



^ Arch. A. Zool. Exp. t. iii. 



2 Areb. d. Zool. Exp. t. ix. 



* Phil. Trans, extra vol. 1879. 



^ Jfouv. Arch. A. Museum, t. viii. 



' Notes from Leydeii Museum, vol. vi. 



^ Pj-oc. Eoy. Pbys. Soc. 1884-85, p. 369. 



'' Proc. Linn. Soc. vol. xi. p. 96. ^ 



