;")K TR1T1A. 



N. Ko.'iiiANA, Dunker. PI. 17, tig. :J:>4. 



Yellowish white, variegated with chestnut. Length, 3-4 mill. 



Tulle. Jiity, No. Africa. 

 Another immature and doubtful species. 



N. I'urATKLLA, A. Ad. PL IT, tig. :-J:{.'>. 



Yellowish, stained vvitli light brown or ash. Length, 1 inch. 



Watl,ci<>!i Bay, ,sv>. Africa. 

 Very closely allied to the European X. re< iculdta. 



'"' Atlantic Oci'tin and Mediterranean >>></. 

 X. CLATHRATA, Born. PL IT, tigs. ^Hi-H;)'). 



Shell turreted, rather tliin. suture flatly, narrowly channeled, 

 whitish, irregularly yellow-banded in the middle; a deep sulcus 

 at the base of the body-whorl. Length, '0-1*^5 inch. 



Mediterranean tic a ; Mtidcira ; ('n<i ri<'. 



Seldom found living, but extensively distributed as a miocene 

 and pliocene fossil. It is a very variable form, and Weinkaufl 

 even suspects that X. nu'<ju, Lamai'ck. will jn'ove to be a variety 

 which is not unlikely. The oldest name used for the species 

 is that which 1 have adopted, and it has the advantage of being 

 binomial, whilst the later and generally adopted name. A'. 

 limatd. Chemnitz, is only a portion of the phrase Liiveii in that 

 work. N. prixmaticd , Brocchi (fig. 387), and \. cft'i/ann. Dujar- 

 din are synonyms among the fossil specimen-. Mr. Marrat 

 figures for N. turrita, A. Ad. (tig. 3:>S).a shell which is certainly 

 identical with this species. A'. #r<il(ir(i'i',Hi*. 'Val. (tig. :!:>'.>). i< 

 not adult. 



\. HKTHM'LATA, Ijillll. PL IS. figs. JUO-.'M-"). 



Yellowish white, light chestnut or chocolate-color: sculpture 

 varying considerably, but the longitudinal ribs are usually the 

 most prominent . llexuo'is. distant, or numerous and close ; occa- 

 sionally the suture is beaded so as to resemble .V. rnatiilr. 

 Kiener Len-jth. '7r>-l'2f) inch. 



Kurope, 'from \<>rir<n/ i<> fhr M<(iilt //"> 



Fossil, from the mioceue throughout iMirojie. 



Jeffreys* says: At the recess of each tide this mollusk 

 buries itself in the sand in a slanting position, its 



* Brit. Conch., iv, 348. 



