66(} 



MOLLUSCA 



near the head, with the resuh that the auriele is forwards, llie aorta Iieliind. 

 The Testacehid;e have the kiiij;s at the posterior end of the body. Oeeasionally 

 streptoneurous eonditioiis oeeur {Chiliiui). The luni;, the most charaelerislic 

 feature of the order, has ahx-ady l)een mentioned (_p. jJO). 



Many puhnonaies are ai[uatie, Init sinee thev ha\e no i^iUs thcv must oeea- 

 sionaUv eome lo the surfaee to UU the hnii; \\ith air, hut some, whieli li\e at 

 great deptlis in the Swiss hikes and eonsequenllv cannot reach the surl'ace, 

 use the skin and to some extent the hmi,' (ov water-lireatliing. Se\eral genera 

 {rhinorlus, rnlniobrjiuhia. Si plioiiaria) ha\-e formed secondary giUs. 



Sub e>rder 1. STVLO.M.MA TOPlIOlvA. h'our retraclih- 'lenlacles, eyes at 

 the tips of tlie second pair. The lli'i.icin.i:, a well-developed shell. Ihii.x* 

 many hundred species, Piif'ii,''' Aihatiiia, l^iilliiius, many tro|iieal species. 

 LiM \cii").i:. Shell reduced, conipleleh' concealed in the mantle. l.hiidx* 

 .I/7"e».* Sub Order 11. K.VSSOM.VtOniOR A. Only one pair of non- 

 retractile lenlacles, eyes at their base. Limn.vio.k, ponii snails. /./»;««•(;,* 

 rianorhis.''' 



Class V. Cephalopoda. 



The Cephalopoda are distinguished among tlic molIust~s liv their size 

 and Itigh organization. The ntajorit}- measure, including the arms, from 



1''i>- ,v47' l''ie.. _mS. 



Fig. 3.17.— (1<V,./)»,v' I„ii:;,,,ihs from Ihe si,K- (aflcr Tl.nlel. Funnel and manlle fold 

 to llic riL,'lu; back ami eves on llir Irfl. 



h'lc.. 348. — Lolii^o koliiciis/s, venlral view (^afler IKnIc). 



eight inches b> tliree feel in Icngllr, a few are smaller (two (o seven inches), 

 while especially rare are Ihe giants, some of which may he o\cr forty feet 

 long. For a long time these large species were only known from the tales 

 of sailors. In the last half-cenlury some of these forms, belonging fo the 

 genus Anliilculhis, ha\-e been stranded on the coasts of Ncwfounillaiul 



