NASSA RET I COS A. 63 



Var. pulchra, nov. Plate III, fi^. 14. 



Remarks. — I have five or six imperfect and immature specimens of a Nassa from 

 Oakley, which may be regarded as an undescribed variety of this polymorphous 

 species. The sculpture is very fine and delicate, more so than in any of the 

 varieties figured by Wood, or that I have hitherto seen. From a superficial 

 examination they might be taken for that described by Wood as N. reticosa, var. 

 simplex (1st Suppl., p. 15, tab. iv, fig. 3), but I do not think that is the case. 

 There is a specimen from Walton of what I take to be the latter in the Sedgwick 

 Museum at Cambridge which I have figured in PL V, fig. 7, as a variety of a new 

 species, N. Dautzenbergi, to show" the difference between them. The latter is a 

 small shell, full grown, with a thickened lip, belonging to the granulata group, 

 having, in my opinion, but little connection with N. reticosa. 



Var. lineata, nov. Plate III, figs, 17, 18. 



Remarks. —In this variety from Butley, in the Ipswich Museum, which in form 

 resembles AVood's variety concinna, the longitudinal costse are absent from the 

 lower whorls and are hardly visible on the upper ones. I have recently found 

 two similar specimens at Oakley, however, which show faint l)ut numerous 

 longitudinal costse on the upper part of the shell. It seems to be common in the 

 Manx beds. 



Var. cancellata, nov. Plate III, fig. 19. 



Remarls. — This also is a specimen from the I])swicli Museum, and came from 

 Butley. It differs from any figured by Wood. 



Var. costata, S. V. AYood. Plate III, figs. 15, IG. 



1848. Nassa reticosa, var. costata, S. V. Wood, Mon. Crag Moll., pt. i, tab. iii, fig. 10 /(. 



1894. Nassa serrata, Kendall, Jouru. Isle of Man Nat. Hist. Soc, vol. i, p. 419, pi. i, figs. 2, 3. 



1903. Nassa serrata, Lamplugh, Mem. Geol Surv., Isle of Man, p. 475, fig. 81 (p. 336). 



Dimensions. — L. 28 — 42 mm. B. 15 — 20 mm. 



Distribution. — Coralline Crag — Boytonian : Boyton, Ramsholt. Red Crag : all 

 zones. Isle of Man. 



Remarhs. — This form varies considerably in the length of the spire, otherwise 

 its characteristic features are more or less constant. 



The shell figured by Wood has a short spire, and does not fully represent 

 the variety costata which is the most prevalent one at Boyton and Oakley. In my 

 collection specimens from those and other localities are generally elongate. 



