0(58 TAC.i'; SM)(:si;i:i{c. 



Coiiclioecia Haddoni G. S. Bradv and A. M. Norman. 



Conchoccia Haddoni. (i. S. Hl{Ah\ and A. M. XmiM w. isiMi; p. (lUd; pi. LXI\'. (ifrs. <>— Hi. 

 <;. W. Mru.EK, l<Hi|. ],. !l; liu. 17 ( a ivproducl ion (it lli.' (iri^iiial 



(iosfii|)t idii). 

 P. T. Ci.km:, i«u»5, p. i:5(). 



(i. W. .Ml'I.lKH, 1906 a, ]). Sil; pi. Will, figs. 1— 1(». 

 V. VA\l;.\, 1906, p. 49; ])1. 1\", iigs. 65—75. 

 (t. W. MOLLER, 1908, p. 70. 



(i. H. Fo\\i.i:u,1909,pp. 235. 264. 287;pl. XVIII. XIX, figs. 73— 89. 

 ('. H. OSTENFELD and C. WeSENKERG-LUND, 1909, ]). 113. 

 (i. \V. Mi'i.i.Kit. 1912. p. 78. 



Description: — See 0. \X. Mt'LLEli, 19()() a, p. 89 and \'. VAviiA, 1906, p. 49. 



Supplementary description: — Male: — 



Shell: — Length: G. S. Buady and A. M. NOHMAN give tliis as 2,55 mm. 

 G. W. Mt'LLER, 1906 a says: ,,Die Tiere scheinen sich ziemlich scharf in cine kleinere nordlichc 

 Basse (2 bis 2,6, <S mir bis 1,9) und eine groRere siidliche Rasse ($ 2,6—2,95, S 2,2—2,5) zu 

 sondern"; the former one would be found in the north, the latter in the south hemisphere. 

 The total amount of variation for the length of the shell in the males would be 1,85 — 2,5 mm. 

 This division is obviously incorrect; the male investigated by G. S. BiiADV and A. M. Norman, 

 which was caught off the coast of Ireland, measured 2,55 mm., as has already been pointed out, 

 i. e. more than G. W. MUller's southern specimens; in addition Y. \'A\7^a gives a length of 

 2,4 — 2,5 mm. for northern specimens; G. H. Fowler states 2,1 mm. The specimens investigated 

 by me measured 2,3 — 2,6 mm. Length : height about 2 : 1. Length : breadth about 2,3 : 1. 

 Seen from the side the shell has about the type reproduced by G. S. Brady and 

 A. M. NORSIAN; see the accompanying fig. 1. S e e n f r o m b e 1 o w it has its greatest width 

 at about the middle and the anterior part is somewhat larger than the posterior part. 

 The side contours are somewhat concave just behind the middle but apart from this they are 

 uniformly curved. The anterior end is broadly rounded, with an almost symmetrical rostrum, 

 the posterior end is somewhat pointed or rather narrowly rounded; cf. the accompanying fig. 2. 

 The shoulder vault is rather well developed and well rounded. The surface of the shell 

 is bare. Seen from inside: Selvage: This is either smooth- edged or finely serrulated 

 on the rostrum and has no spines of any great size. It is smooth-edged along the anterior margin 

 of the shell and the anterior half of the ventral margin; along the posterior half of the ventral 

 margin of the shell it is finely serrulated and along the ventral half of the posterior margin of the 

 shell it is coarsely and irregularly serrulated. The glands are of the type described by G. W. 

 Muller. The medial glands along the posterior margin of the shell are rather large; most 

 of them have a single exit; their exits are arranged in a rather distinct row running about lialf 



