172 SALENIA 



connecting links, and fall within the general description given of the punctuations on the 

 sutural lines of the discal elements. 



Affinities and Differences. — Salenia petalifera forms an excellent type of the true 

 Salenia, and a leading fossil of the beds in which it is contained. I cannot appreciate 

 the differences which some naturalists point out between this species and S. scutigera, 

 Miinster ; and as I have never seen a true type of that species, I must reserve my 

 opinion until I can make a comparison between them. After many careful examinations 

 of Herr Hohe's figure in the ' Petrefacta,' and knowing the extreme accuracy and truth- 

 fulness of that excellent artist's admirable drawing, I am inclined to think that Cidarites 

 scutiger, Miinster, is only a smaller form of S. ])etalifera, Desm. ; but as most competent 

 authorities have ruled it otherwise, I have not put 8. scutigera in my list of synonyms. 



8. petalifera resembles 8. Austeni, Forb. ; the latter, however, has a more elevated test 

 with a smaller apical disc, and more prominent periprocte. It very much resembles 

 8alenia giblia, from the same stratum of Upper Greensand, which may Ije only a variety 

 of 8. petalifera : a closer comparison between these two allied forms will be found in the 

 description of 8. gihha. 



Locality and 8tratigraphical Position. — 8ulenia petalifera was at one time an abundant 

 fossil in the Upper Greensand of Longleat, Wilts ; but has now become more rare. It is 

 collected from the Grey Chalk near Folkestone, where some very fine examples are some- 

 times obtained. I have long noticed that nearly all the Upper Greensand Echinidse 

 are found in the Grey Chalk, and that the specimens from the latter stratum are in general 

 larger and more fully developed, as if they had been better nourished, than those collected 

 from the arenaceous beds of the Upper Greensand of Wilts and other localities. 



History. — This Urchin has long been considered to be a leading English fossil of the 

 Upper Greensand ; and Parkinson, 1811, Smith, 1816, Konig, 1820, have all given good 

 figures of this Echinite. 



Foreign Distribution. — In the Craie Chloritee de Cap-la-Heve, and other parts of 

 France, in Bavaria and Minorca, and in the " Hils-Congloraerat " of North Germany. 



Salenia Loriolii, Wright, nov. sp. PI. XXXV, fig. 1 a — d. 



Diagnosis. — Test small, circular, depressed ; upper and under surfaces flattened ; 

 ambulacra straight, narrow, two rows of marginal homogeneous granules ; inter- 

 ambulacra wide, four or five tubercles in each row ; decreasing gradually in size from above 

 downwards ; apical disc large, border slightly undulated, surface flat, smooth ; ovarial plates 

 without sutural lines or punctuations in the middle of the disc, and with ten round aper- 

 tures near the outer border ; mouth-opening large, peristome deeply incised, lobes unequal. 



Dimensions. — Altitude, two lines ; latitude, four lines. 



Description. — This small Urchin exhibits a form of apical disc very unusual among the 



