CH. VII.] OVULITES. 163 



defined them as follows : — " Polypier pierreux, libra, ovuliforme 

 ou cylindrac^, creux int^rieurement, souvent percd aux deux 

 bouts. Pores trfes petits, regulierement disposes k la surface'." 



The specimens are referred to two species, Ovulites mar- 

 garitula and 0. elongata. 



By some subsequent writers^ these calcareous fossils, like 

 miniature birds' eggs with a hole at either end, were included 

 among the Zoophytes. Carpenter and others afterwards referred 

 Ovulites to the Foraminifera, and compared the genus with 

 Lagena^. The single specimens of Ovulites have a length of 

 2 — 6 mm. At each end there is usually a fairly large and 

 somewhat irregular hole (fig. 35, F), and in some rarer cases 

 there may be two apertures at the broader end of an Ovulite. 

 A good example of Ovulites margaritula with two pores at the 

 broader end is figured by Michelin*. The surface of the shell 

 when seen under a low magnifying power appears to be covered 

 over with regularly arranged circular pores, which are the 

 external openings of fine canals (fig. 33, L). 



In 1878 Munier-Chalmas expressed the opinion, which was 

 supported by strong evidence, that Ovulites should be referred 

 to the siphoneous algae ^ He regarded it as generically 

 identical with Penicillus (Coralliodendron, Kiitzing). It has 

 already been pointed out that in Penicillus the apical tuft of 

 filaments is partially calcareous (fig. 33, 0)". The individual 

 calcareous segments agree almost exactly with the fossil Ovulites. 

 Asa rule the Ovulites occur as separate egg- or rod-like bodies, 

 but Munier-Chalmas informs me that occasionally two or three 

 have been found joined end to end in their natural position. 

 The terminal holes in the fossil specimens represent the 

 apertures left after the detachment of the calcareous segments 

 from the uncalcified filaments of the alga. The segments 

 with two holes at the broader end were no doubt situated at 

 the base of dichotomising branches as shown in fig. 33, K. 



1 Lamarck (16) p. 193. 



2 Defiance (26) PI. xlviii. fig. 2, and PI. l. fig. 6. 



3 Carpenter (62) p. 179, PI. xn. figs. 9 and 10. 

 ^ Michelin (40-47) PI. xlvi. fig. 24. 



' Munier-Chalmas (79). 



8 Lamouroux (21) PI. xxv. fig. 5, p. 23. 



11 — 2 



