i:l!A('IiroP>I>A .JACKSON. 187 



specimens of the last-named species have a tvpe of cardinalia Almost as massive as thai 

 in species iisf-rilied to Pachymagas ami Xin/l/i/ri*. 



Though I he immature sliells no\v under discussion were dredged along with 

 a dead specimen ol Neothyns lenticularis, tliev can scarcely lc regarded as young 

 I'Tins of that species, owing to the fact that the latter is not known to have a 

 multicostate stage. Neither can they be referred to '!'< r<l>r<it>-ll<t ntbicunda, as mvHticos- 

 tation here comes on verv late in life, or not at all in some eases. There remains, 

 therefore, only one oilier New /calami lorm with which comparison can lie made, 

 \i/., Terebratella -<ii/</ii/i/i i </. In this species disunion appears earlv* and gradually 

 increases in iutensilv. 



Unfortunately the smallest example of T. xmii/ninai in mv collection is one 

 measuring I0'7 mm. long, ventral valve (dorsal = 9 mm.). In this specimen the loop 

 is apparently no further advanced than the Magelliform stage <if T. ni/>i<-u>id<t, figured 

 l>y Thomson [1915 (2), fig. (] on p. 407], or the iMagaselliform stage of X. len/ifitbir/x, 

 as figured by Beeeher [1893. pi. i, fig. Fli]. The cardiualia are pretty much the same 

 as in the example from Station 90. and there is also a tubercle lying iu the hinge- 

 trough, but it is much more elongate. 



The puiictje in my specimen are very evenly distributed, but are less in number 

 than in the example from Station 90, being from 112 to 140 per square mm., about 

 the middle of the ventral valve. It might be stated, however, that there is considerable 

 variation in the punctatiou of '/'. KIIIKJIIUII'U in different stages of growth. On the early 

 (apical) parts of adult shells which I have examined, the punctse are very even, but 

 later, as the costaj become more pronounced, the punctre are densely segregated in the 

 coshe, leaving the furrows witli considerably fewer. In one adult example examined 

 I found from 232 to 288 puucto) per square mm. in the costaj, while the furrows only 

 contained 132 to 160 per square mm. 



If the examples from Station 90 should ultimately prove to be young stages 

 of T. sanguined, then the range of this species, like N. lenticularis, is considerably 

 increased northwards. The most northernly locality recorded for T. x>i<jnliH'<i 

 appears to be Cape Colville. Auckland (some 250 miles S.E. of Station 90), where 

 an interesting variety was dredged in 20 fathoms [Thomson, 191 G, p. 4G, pi. i, 

 fig. 3]. 



It might be stated, however, in conclusion that the advanced stage of the loop in such 

 small specimens is suggestive of a higher form than T<'rfl>r<tt<-ll. One is tempted to 

 ascribe the shells to the well-known Australian species, Magellania flavescens, &s they 

 resemble the young stages of that species very closely ; but beyond the somewhat 

 doubtful record of "Chatham Islands," given by Thomson [1915 (2), p. 409], 

 3f. flavescens has never been described from New Zealand waters. 



' Thomson [191o (-), p. 405] gives 3 mm. as the length of the ventral valve ou which multicostation 

 is apparent. 



2 F 2 



