Prof. P. M. Dancan on the Salenid^e. 6^' 



cles (primaries), four or five in a series. They are strongly 

 crenulate, and have a projecting and imperforate maraelon. 

 They are very unequal in size ; and only one or two in each 

 series above the ambitus are largely developed. Granules 

 are scarcely unequal, distant, and sometimes have mamelons, 

 and they form a double subsinuous line in the midst of the 

 interambulacrum. 



The ambulacra are very narrow, not flexuous, and are 

 furnished with two rows of small granules, eleven or twelve 

 in a series ; they are alternate or but slightly distant ; and 

 there are some intermediate wart-like grains. The pores are 

 simple openings at the base of a small granule-like swelling. 



The apical disk is relatively large, has five genital and 

 five ocular plates, which are perforate, and an imperforate 

 subaual. These plates are marked with numerous radiating 

 grooves or furrows, which give them a very remarkable digi- 

 tate appearance (" un aspect digits "). The anus is eccentric in 

 front, is triangular and slightly swollen at the margin. 



The peristome is depressed, slightly smaller than the apical 

 system, subdecagonal, and tolerably distinctly marked with 

 cuts. Height 3*5 millims., diameter 6 millims. 



Cotteau remarks that this small species is more or less 

 allied to the Cretaceous forms, and instances Salenia 

 scutigera and S. minima of the Chalk of Maestricht and 

 Ciply. The distinction is in the relatively large peristome 

 and in its projecting ambulacral tubercles and grooved disk. 



This Salenia is quite typical of the genus. The subanal 

 plate, when placed in its proper position in relation to the 

 madreporic, determines the eccentricity of the anus to be pos- 

 terior and to the right. M. Cotteau's drawings add to the in- 

 formation given in his context ; for they show that the number 

 of pores is about double that of the number of ambulacral 

 tubercles, and that the posterior and the right posterior gene- 

 rative plates are the largest. Hence there are two sets of 

 pores to each ambulacral tubercle, instead of one, as in the 

 subsequent Salenim. The ocular plates, of course, do not 

 enter into the formation of the anal ring, which infringes on 

 the usual plates. The dimensions of the peristome and the 

 size of its cuts are characteristic. 



Salenia Pellati is therefore more closely allied to the Cre- 

 taceous than to the Miocene or recent forms, the small number 

 of pores, as A. Agassiz has pointed out, being characteristic 

 of the Cainozoic and recent forms. 



Doubtless only a short time will elapse before a description 

 of the lately discovered Salenia from the Numraulitic of Siudh 

 will be given to science. 



5* 



