SuTEii.-— ^iro Xew Fos'ii/ Molluscf 



595 



Arj\ lit. — Two New Fossil Mollusca. 

 By Henry Suter. 



|/.Va(/ before On Otaijo Imtitute, 4th Odobfi; 1910. \ 

 Plates XXX, XXXI. 



I. A New Fossil Turritella, 



Turritella semiconcava n. sp. Plate XXX. 



Shell large, high and narrow, many-whorled, with 8 to 10 cinguli on 

 the lower, slightly concave whorls, and a deep suture towards the base. 

 Sculpture : The first few post-nuclear whorls have 4 equidistant spiral cords, 

 the third much stronger than the others (fig. 16) ; the following whorls 

 have 5 snbequidistant cinguli ; gradually the number of cords increases on 

 tlie whorls, the body-whorl of an adult specimen having usually 10 cords ; 



the same sculpture is continued 

 upon the base. Spire high, nar- 

 rowly conic. Protoconch not seen. 

 Whorls about 18 to 20 on a full- 

 grown specimen, slowly and regu- 

 larly increasing, flat on the upper 

 whorls, lightly concave further 

 down ; the body-whorl narrowly 

 rounded towards the flattish base. 

 Suture on the upper part of the 

 shell not much impressed, but gra- 

 dually getting deeper approaching 

 the base. Aperture subquadrate. 

 Outer lip with a moderate broadly 

 rounded sinus. 



An adult specimen would have 

 a diameter of 18-19 mm., and a 

 height of about 95 mm ; angle of 

 spire, 11°. 



Log. — Mitchell's Point, Kai- 

 tangata Beach, Otago (Professor J. 

 Park). 



Professor James Park most kindly 

 sent me specimens of this new Tur- 

 ritella for description, accompanied 

 by the following remarks : "It 

 occurs in thousands in thin cal- 

 careous tabular and lens-shaped masses in a greenish sandstone. Its asso- 

 ciates are Conchothi/ra parasitica, Chcnopus sp., Belemnites lindsaiji, and 

 many other forms. The Upper Kaitangata coal-bearing series are assigned 

 to Upper Cretaceous." 

 Type in my collection. 



Remark. — In sculpture this species is )iearest to T. cavershamensis Harris 

 (= gigantea Hutton), and in the concavity of the lower whorls it approaches 

 T. eoncava Hutton, but it is decidedly distinct from both. 



The photo reproduced on the plate was taken by Mr. A. G. Macdonald, 

 and kindly sent to me by Professor Park. 



Figs. 1, 1(7. Turritella ■'■eiiu'concavei. 

 Fig. lb. Post-mick'ar whorl. 



