56 GOES, RETICULARIAN KHIZOPODA OF THE CARIBBEAN SEA. 



Nodosarina complanata DEFR. 



Tab. Ill, figg. 62 -G4. 



It is not without some hesitation that this form should be distinguished as a 

 species; for a closer study leads to the conclusion, that it possibly may originate 

 from different species of Nodosarina, thus being descendants, each bearing small marks 

 of variation pointing back to their origin, but all still maintaining in common a fea- 

 ture of essential unity. 



1. From Nod. radicula some simple forms of ^Frondicularia^ have seemingly 

 their direct origin. 



2. Other varieties keep close to Nod. (Glandidina) Icevigata D'ORB., as Frondicu- 

 laria spatkulata WILLIAMS., Frond, simplex Rss. f Frond, folium ALTH. 



3. Frondicularia ensiformis ROM., Frond, lingua BOLL, bear the same relation to 

 Nod. legumen. 



4. All smooth varieties with their earliest chambers arranged in the same way 

 as in Nod. crepidula are, it would seem, immediate offsets of this species. Cristellaria 

 Gaudryana D'ORB., Flabellina macrospira Rss. etc- are instances of this transition. 



In systematising the costate forms of Nod. complanata the same difficulty is 

 met with as in the other Nodosarinte. Sometimes the primordial chamber only is 

 ribbed, the other parts being quite smooth; at another time the striation of the shell 

 is quite faint and scarce. 



When both forms of Nod. complanata (Frondicularia and Flabellina) with their 

 numerous modifications of form are collected from the same localitiy, they certainly 

 create the impression that they all belong to a single species. 



This set of Nodosarina gives us a noteworthy hint of, how unsatisfactory must 

 be the result of the attempts of our days to make out the genealogy of a species, for 

 it can scarcely be denied, that sometimes one form may possibly have originated 

 from several different species. 



Fig. 62 is next to Frond, alata D'ORB., it is taken from a small specimen,., but 

 on the chalkbottom it often attains the size of 10 mm. in hight and 8 mm. in breadth. 



Fig. 63 the same with the younger state of crepidula growth. 



Fig. 64 is still nearer Nod. crepidula. Sometimes the primordial chamber is pro- 

 vided with a couple of secondary chambers set at right angles to the ordinary ones. 

 If this plan of growth had continued a four-winged form would have originated. 



A stout lanceolate-elliptical form is also met with among the coralline-gravel. 



Syn. Frond, obliqua v. MUNST., EOM., 1838, Nordd. tert. Meeress.; Leonh. u. Bronn. Jhrb. 1838, 



p. 382, t. 3, fig. 7. 



oblonga, ovata ROM., ibid. t. 3, fig. 4 6. 



obliqua ALTH., 1849, Umgeb. Lemberg; Haid. Nat. Abh. 3. 2, p. 268, t. 13, fig. 26. 



lancea PHIL., 1843, Tert. Versteiner. nordw. Deutschl. t. 1, fig. 31. 



Meyeri BOLL., 1846, Ostseelandern. p. 177, t. 2, fig. 18. 



