NODOSARIINAE jgg 



which is probably not the original Type, coming as it does from Upper Hungary. These 

 specimens in the tube agree on the whole with d'Orbigny's figures ; both megalo- and 

 microspheric individuals are represented; the spine being either absent or broken, but 

 the sutures are limbate, not depressed as indicated in d'Orbigny's figure. 



Genus Cristellaria, Lamarck, 1812 



268. Cristellaria crepidula (Fichtel and Moll) (Plate XII, fig. 15). 



Nautilus crepidula, iMchtel and Moll, 1798, TM, p. 107, pi. xix, figs. g-i. 



Cristellaria crepidula, Brady, 1884, FC, p. 542, pi. Ixvii, figs. 17, 19, 20; pi. ixviii, figs, i, 2. 



Cristellaria crepidula, Heron-Allen and Earland, 1916, FSC, p. 47, pi. vii, figs. 5-10. 



Twelve stations: 48, 388; WS 71, 83, 84, 86, 87, 88, 92, 93, 245, 246. 



Frequently abundant, particularly good at WS 84, 86, 87, 88. At the latter station an 

 extraordinary series of specimens was obtained, ranging from megalospheric individuals 

 attaining a large size to microspheric individuals of tiniest proportions. At this station 

 also three specimens, one of which we figure, were obtained of paired individuals, 

 attached to each other by a development of fine hair-like processes. The largest pair 

 was 0-20 mm. in length, o-i8 mm. extreme width of pair. Two similar pairs were found 

 at 388 where the species is frequent. 



269. Cristellaria tenuissima, sp.n. (Plate XII, figs. 16-20). 

 Eight stations: 388; WS 88, 90, 93, 97, 221, 246, 248. 



Test minute, hyaline, extremely compressed, consisting of eight to twelve lono-, 

 narrow, wedge-shaped and tapering chambers, arranged in a curve from the prolo- 

 culum, each chamber, in turn, forming the chord of the arc, and extending almost the 

 whole length of the shell. Peripheral edge rounded, aperture normally radiate, sutural 

 lines flush but distinct. 



Length, o-3o-o-40 mm.; breadth, o-8-o-i4 mm.; thickness, about 0-03 mm. 



Many specimens of this extremely delicate and graceful little form, but it is rare 

 everywhere. A single specimen which we figure (fig. 20) from WS 248 may represent the 

 megalospheric form. It has only five chambers following a large reniform proloculum 

 and agrees with the Type in its high degree of compression, and in the shape of the 

 chambers. On the other hand it may be referable to C. cymboides, d'Orbigny, with 

 which it is otherwise in agreement. There is considerable variation in the size of the 

 proloculum in the other specimens, which we have regarded as the microspheric form of 

 C tenuissima (figs. i6-ig). 



C. tenuissima is fairly distinctive, its nearest relative being probably C. cymboides 

 d'Orbigny (d'O. 1846, FFV, p. 85, pi. iii, figs. 30, 31), from which it difl'ers by its 

 extreme compression. A somewhat similar object is figured by Sidebottom under the 

 name Vaginulina costata (Cornuel) (S. 1918, FECA, p. 139, pi. v, figs. 4, 5), but the test 

 is very much larger. The form of the chambers is also more vaginuline and the sutures 

 limbate. 



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