88 GOES, RETICULARIAN RHIZOPODA OF THE CARIBBEAN SEA. 



As far as I know, there is not on record any Valvulina with subdivided cham- 

 bers but Valv. Younc/i BRAD, from the lower carboniferous limestone in Scotland and 

 England (Palteogr. Soc. 30, p. 86, t. 4, figg. 69). 



Fig. 390: clavate, smooth and hard specimen, with produced valvuline stage. 



Fig. 391: stout form with thick deposit of chalk. 



Fig. 392: median section of the same. 



Fig. 393: longitudinal section of a better defined specimen displaying the ovoid 

 or uterus-shaped central space of the chambers, their radiating, bifid divisions, and the 

 very short triserial stage. 



Fig. 394: transverse section through the earlier stage, exhibiting the triserial ar- 

 rangement. 



Fig. 395: section at the commencement of the uniserial stage. 



Fig. 396: section through the more advanced stage. 



Fig. 397: young clavate form cut longitudinally. 



Fig. 398: young ovoidal form. 



Fig. 399: still younger form, nearly globular. 



Fig. 400: longitudinal cut of a very young specimen, only l.i mm. 



Valvulina triangularis var. eocaena GUMB. 



Tab. XI, figg. 401403. 



The multiserial stage is so very little developed as often to be wanting, and the 

 specimen may be taken for a Lituolina; or at the best the early stage is reduced to a 

 few chambers, rendered extremely indistinct or masked by the agglutinated coarse sarid- 

 grains. Unquestionably our form ought to be placed quite near to ^Clavulina com- 

 munism D'()RB. 



The shell of our form is tightly built of coarse sandgrains mixed with a greath 

 many sponge-needles. Its shape varies from a more slender, to a stout pupoid form, 

 which latter is prevalent. The aperture is generally very narrow, not iinfrequently 

 poreformed, sometimes obsoletely triangular. The chambers are ordinarely undivided, 

 but occasionally there are at nearly regular intervals a few sandgrains projecting from 

 the walls, representing rudimentary partitions. 



From the northalpine Eocajn Mr. GUMBEL has designated a variety of Clavulina, 

 that seems nearly identical with our form (Clavulina eoccena GUMB. 1868, K. Bay. Ak. 

 Wiss. Abh. 1. 10. 2, p. 601, t. 1, fig. 2). It is riot unfrequently met with in the coral- 

 line-gravel and chalk-ooze, attaining a length of 3 mm. 



Figg. 401 402: thicker and narrower specimens, the first one with scarcely a 

 valvulina-stage. 



Fig. 403: the aperture 



