MONODONTA. 103 



bordered anteriorly by a nacreous strip uniting with that of the 

 upper lip, as in the case in JNI. nigerrima ; place of the umbilicus 

 marked by a slight pit ; opaque substance of the columella extend- 

 ing upon the base of the aperture, forming a strong ledge within. 

 Alt. 12, diara. 15; alt. 10, diam. 13^ mill. 



Xeiv Zealand. 



? Labio porcijera A. Ad. P. Z. S., 1851, p. 179. — Trochm porcij'er 



Watson, Challenger Moll., p. 67, t. 4, f. 12.— Diloma nigerrima 



HuTTON, Manual N. Z. Moll., p. 96; and Trans. N. Z. Institute, xv, 



p. 125, t. 15, f. B. (Dentition.) (Not T. nigerrima (Gni.) Phil.) 



The present species has been confounded by most authors with the 

 Chilian M. nigerrima. From that form it may be readily distin- 

 guished by the following characters : The spiral lirae are much 

 coarser and generally more conspicuous, although occasionally 

 obsolete on the last whorl ; they number 15 to 18 on tiie body-whorl ; 

 the form is more depressed ; the spiral undulations of the nacre 

 within the outer lip much more obvious and coarser ; the columella 

 less concave ; the parietal wall without the nacreous band which 

 connects the terminations of the lip in jNI. nigerrima, and upon care- 

 ful inspection a few white or yellowish dots may be detected upon the 

 black surface, especially on the base, thus showing the affinities of the 

 species to be with M. striolata and M. ^ethiops rather than w'ith M. 

 nigerrima. The surface is rather smooth and polished, with light 

 growth-lines. 



The animal is black ; head with a transverse band of yellow near 

 the front margin ; rostrum margined with white ; tentacles long and 

 tapering, longitudinally striped with black and yellowish ; filaments 

 blue-black, three on a side, sonietimes a fourth on the left side ; foot 

 white, closely and finely marbled with blue-black, and broadly 

 margined with yellow veined with black. Its movements are said 

 by Hutton, from whom I have taken the above descri[)tion of the 

 animal, to be very rai)id, quite different from the other species of 

 Neodiloma. 



M. coRACiNA (Troschel) Philippi. PI. 19, fig. 94; pi. 31, fig. 28. 

 Shell small, imperforate, orbicular-conoid, depressed, solid, luster- 

 less purplish-black, unicolored, or sparcely dotted (especially 

 beneath) with yellowish ; spire conic, short, eroded, whitish ; suture 

 scarcely impressed ; whorls 4-5, slightly convex, the last large, 

 spirally lirate, the line more or less obsolete, about 5 to 8 on the 



