2 BULLETIN 11, UNITED STATES NATIONAL MUSEUM. 



to the region of Torres Strait. In the North Pacific, however, 

 these species are, as a rule, confined to the western portion from 

 southern Japan southward. The rediscovery of some of the species 

 described by Brady, from almost the exact locality at which they 

 were dredged by the Challenger, is very interesting and tends to 

 show the restricted distribution of certain forms. 



A systematic presentation of the various groups of the family 

 follows : 



Family 4. TEXTULARIID.E. 



Test either arenaceous or calcareous, perforate, the chambers usually 

 numerous, essentially biserial or triserial, or in some genera spirally 

 arranged. 



The family Textulariidse is apparently the most primitive, after 

 the Lituolidse. A number of the genera are wholly or in part com- 

 posed of species with arenaceous tests, which is in itself a primitive 

 character in the group. In many species both the microspheric and 

 megalospheric forms are known. In the microspheric form, which 

 repeats most completely the phylogenetic characters, a coiled early 

 development succeeding the proloculum is commonly found. This 

 stage may be compared to the entire development of such a genus 

 as Haploph rat/ moides in the Lituolidse.- 



In the most primitive subfamily, the Spiroplectinae, the coiled 

 development is continued for a fairly long period, and makes up a 

 considerable portion of the test. This coiled stage also occurs in 

 both the microspheric and megalospheric forms, showing that this 

 subfamily is decidedly primitive, and has not as yet become so 

 specialized as to lose the coiled stage in the megalospheric form. 

 In Spiroplecta, the only genus of this subfamily, the coiled develop- 

 ment is followed by a series of more or less numerous chambers 

 arranged biserially . Spiroplecta in its stages of development recapitu- 

 lates the essential features of the Textulariidae ; a proloculum, followed 

 by a closely coiled series of chambers, in turn followed by a biserially 

 arranged group. This sequence is the basis of the development 

 throughout the family, as will be shown, and is not an exceptional 

 character. 



In the Textulariina3, the typical genus of which, Textularia, may be 

 taken as an example, the same stages are shown, but are modified 

 by specialization and acceleration of development. The earlier 

 stages are either much reduced or are entirely skipped. In the case 

 of Textularia candeiana d'Orbigny, for example (figs. 14-17), in the 

 microspheric form the small proloculum is followed by a series of 

 chambers, few in number compared with those of Spiroplecta, but 

 just as distinctly coiled (fig. 1G). The later chambers, which in this 



