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HARDWICKE'S SCIEN C E - G OSSIP. 



[June 1, 1867. 



puts on all the intermediate shapes between this 

 elongated condition and a primary tear-drop form, 

 some species being plain, others ribbed, cross- 

 barred, chequered, and variously ornamented by the 

 extraneous solidification of the shell-growtb. This 

 selection indicates, too, something of the wonderful 

 variety of modifications put on by the species within 

 the limits of every separate genus. 



Fig. no. 

 L. squamosa. 



Fig. 111. 

 L. semistriata. 



Fig. 112. 

 L. Itevis. 



Another group follows in which all these spheres 

 or elongated globules adhere together in lines or 

 rows— single axes which may be straight, or 

 may be bent or curved. Of those thus formed on 

 a straight line, we may take a few examples from 

 amongst the Nodosarice, and in which we shall 



Fig. 113. Fig. 114. Fig. 115. Fig. 116. 



Nodosuriu hispida. N. rugosa. N.longisulcata. N. spinicosta. 



again see further illustrations of that wonderful 

 exuberance of modification which characterizes, as 



Fig. 117- 

 Kodosaria striaticollis. 



Fig. 118. 

 Lingalina carinata. 



we have already noticed, every kind of develop- 

 mental plan. 



The Lingulinae (fig. 118) also present another con- 

 dition of this development of lobes— we prefer not 

 to call them chambers— upon a single straight axis. 



From the straight to the bent is but an easy step, 

 and then all these exuberant modifications in the con- 

 tiguity of lobes, and of their external ornamentation, 

 can be run over again. The Bentalina is an example 



of the simply bent row (fig. 119) ; and mMarginuliiia 

 (fig. 120) we have the rudiment of a tendency to 

 spirality, and which has made still further progress 

 in the examples given of Vulvulina (fig. 121), and 



Fig. 119. Dentallna Fig. 120. Marginulina Fig. 121. Vulvulina 

 semicostata. Webbiana. oblonga. 



RotaUna (fig. 122), until an actual nautiloid spiralis 

 perfected in Robulina. 



And now again set in the currents of modifications 

 of lobation and variations of ornamentation. The 

 spiral may be on a flat plane or a direct vertical plane 

 (fig. 123), or it may be of greater or less rising pitch, 



Fig. 122. 

 Rotalina Canariensis. 



Fig. 123. 

 Robulina Canariensis. 



or screw-like, or it may be absolutely involute or 

 coil-like, as in Fusilina (fig. 124). And the shells 

 formed on each or all these plans may be plain, 



Fig. 124. 

 Fusilina cylindrica. 



Fig. 125. 

 Robulina Ariminensis. 



waved (fig. 125), keeled, spurred (fig. 126), ribbed, 

 barred, indented; may be perforate or imperforate; 



Fig. 126. Robulina echinata. Fig. 127. Globigerina bulloides. 



may have tubular asperities, or be hirsute ; or the 

 lobes, although spirally arranged, may be so far 



