ANATOMY (K PKLl'X' Yl'< M > A BURN] '-'10 



EULAMELLIBRANCHIATA. 



VENERACEA, VKNKIMD.K. 

 0. ('liioii' (Chamelea) spissa (Desh&yes). I'l. Ill, tig. I'.i. 



Si.-iliuM I :; t. Numerous specimens I'rnin II to 20 fathoms, off the north of New 

 Zealand. 



The ;jeneral anatomj i>l' the animal, as is shown liv (In- diagram (Fiir. I'.')- | '''-' nls 

 the type common to other members of the family (.-ee Venus verrucosa, iWliayes, 1, 

 PI. XCII, etc.). 



J'*<n'f. The bvssal apparatus is in very much the condition <>f that described above 

 fnr Venericardia. 



Si'i>*<--< h't/ttitx. There a ri 1 n<> abdominal organs; S|>enuel's organs arc fairlv 

 well developed. The otocysts are Iarge 5 and a IT situated upon the cerebro-pedal 

 connectives, adhereni to their lateral snrfaee close aliovc tlie pedal ganglia. 



J!i.i,<il (>r : /iiit^. The kidney rcscmlilcs that of Penws (Odhner, 8 3 p. :'.lo). and is 

 remarkable for the sli^ln plcatin- and general want of elaboration "f tin- distal arm. 

 This iTM-ioii of the kidnrv is a voluminous sac (pleated a little laterally) communicating 

 frcelv with its fellow bv a wide passage below the pericardium (Fii;. ID. /.<.). Its 

 external opening lies mi the same level as the reno -pericardia] dud and slight 1\ behind 

 the o-euital orifice. 



The reno-pericardial funnel leads into a long and peculiarly narrow proximal arm. 

 which runs backwards wrapped ill a fold of the distal arm parallel the anterior 

 surface of the retractor pedis, and enters the distal arm far back beneath the. renal 

 communication. A well-developed Keber's organ (Fig. 19, /..) is present in relation 

 to the anterior end of the pericardium. 



CiUI*. - The gills are very unequal in size; the plications in the inner and outer 

 demibranchs arc of about the same depth. The reflected edge of the inner demibranch 

 is free of the body, but that of the outer is adherent to the origin of tin- mantle, nearly 

 as Jar back as the adductor: beyond this point it is free, and is extended upward-, as 

 in other Venerida:-. to form a thin, free, and impleatcd appendage (Fig. lii. ///'//.). 

 The intimate structure of the gills also resembles that of other \'cnerid;e ( b'idewond, 

 17, p. :245). In the outer lamella there are seventeen iilamem to (lie pleat : in the 

 inner, twenty-one. 



ANATIXACKA, AXATINID.K. 



10. Anatina elliptica, King and P.rodcrip. PI. IV. jigs. 20 23, 25. 



One specimen from f> fathoms off ('ape Kvans. Mc.Murdo Sound. The specimen 

 (Fig. 20) was somewhat damaged in the region of I he adductor, hut was otherwise in 



'jood condition. 



Mmitli'. The mantle is similar to that of other species of . \nn/in<f ; it i- < - 



plctely close.! except for the siphon-orifices and a small pedal openiiej ( I em. in l 



> , 



VOL. II. - i 



