A Revision of the Foraminiferal Family Heterohelicidae 



By Eugenia Montanaro Gallitelli ' 



Introduction 



THE FAMILY Heterohelicidae, as established by 

 Cushman (1927a), is accepted at present by only a 

 few authors (Colom, 1946, Le Calvez, 1953), and they 

 agree to accept it only provisionally. Cushman in- 

 cluded in the family an homogeneous group of genera 

 related to the type genus, Heterohelix, but he also 

 placed in it a number of fonns which actually should 

 have been placed among the "incertae sedis" because of 

 transitional or poorly known morphological or anatom- 

 ical characters. 



Emendations of this family of considerable interest 

 have been proposed in revisions of the systematics of 

 Foraminifera by Galloway (1933), and chiefly by 

 Glaessner (1936, 1937, 1945), followed without funda- 

 mental change by Sigal (1952) and Pokomy (1954). 

 But many conclusions are still imsatisfactory. 



The analytical research of Loeblich (1951) on the 

 coiling in some Heterohelicidae, and by Hofker (1951a) 

 concerning the toothplate in Bolivinita and Bolivinoides, 

 must be mentioned as indicative that this confusion is 

 partially due to an absence of knowledge of morphol- 

 ogical and structural characters of many genera of 

 fundamental significance in the systematics of this 

 family. A careful restudy of all the type species is 

 required before a new systematical arrangement can 

 be proposed. 



Acknowledgments 



A grant from the Itahan National Research CouncU 

 and a Fulbright travel grant allowed the writer to make 

 this study at the National Museum in Washington. 

 The writer found the collections and Ubrary facilities 

 there to be the best available anywhere for such a 

 study. And above all, the writer is deeply indebted 

 to Dr. Alfred R. LoebUch, Jr., for his assistance and 

 suggestions during her stay and study in Washington, 

 for suggesting the present research topic, and for allow- 

 ing the use of his undescribed material and illustrations. 

 Dr. Helen Tappan Loeblich has kindly read, corrected, 

 and edited the manuscript and has discussed with the 

 writer various systematic and morphologic questions 

 in connection with this research. 



Illustrations are camera-lucida drawings made by 

 Mr. Lawrence B. Isham and Mrs. Patricia Isham, 

 scientific illustrators, U. S. National Musemn. 



' Univereity of Modena, Italy. 



Material Examined 



The recent visit of the writer to Washington made 

 possible a reexamination of all the types of the Hetero- 

 helicidae Cuslmian, then deposited in the U. S. National 

 Museum; almost all the type species of the various 

 genera are there represented. Of the type species 11 

 are represented by holotypes, 7 by paratypes or topo- 

 types and 5 by hypotypes. Other congeneric species 

 more or less related to these type species have also 

 been restudied when necessary. 



The type species of Heterohelix Ehrenberg {H. ameri- 

 cana (Ehrenberg)) and of Pledofrondicularia Liebus 

 (P. concava Liebus) are not available; consequently, 

 some weU knowTi related species were examined {Heter- 

 ohelix navarroensis Loeblich and Pledofrondicularia 

 garzaensis Cushman). 



Three genera {Bolivinopsis Yakovlev, Nodomorphina 

 Cushman, and Nodogenerina Cushman) are represented 

 in the Museum only by doubtfully congeneric species; 

 of these Bolivinopsis is considered an arenaceous form 

 by Pokorn^ and Sigal: thus these genera have not 

 been taken into consideration here. 



The following genera have been invalidated in the 

 present research: Gnembelina Egger { = Heterohelix 

 Ehrenberg), Rectoguembelina Cushman {= Tubitextul- 

 aria Sulc), Ventilabrella Cushman {=Planoglobulina 

 Cushman), Bronnimannella Montanaro Gallitelli 

 {=Pseudotextularia Rzehak). 



Three related and more recently described genera, 

 which were not included in the Heterohelicidae by 

 Cushman, are added for discussion: Tosaia, Takayanagi, 

 Tappanina Montanaro GaUiteUi, and Trachelinella 

 Montanaro Gallitelli. 



The genus Psendotextularia Rzehak is emended and a 

 new genus, Racemiguembelina is proposed. 



Method of Study 



The examinations were made by use of the highest 

 magnification (X 216) available for the stereobinocular. 

 The previous use solely of low magnifications explains 

 many of the misinterpretations in these extremely small 

 Foraminifera. 



When the arrangement of the early chambers was 

 not otherwise clear, specimens were immersed in anise 

 oil, a method foimd to be very successful in emphasizing 



133 



