1894.] ECHINODEBMS OF MACCLESFIELD BANK. 411 



Salmacis rufa, sp. nov. (Plate XXYI. figs. 2 & 3.) 

 There are several specimens of what I take to be an undeseribed 

 species of Salmacis. It may be diagnosed as follows : — 



Spines pale whitish, with red rings or bands of inconstant 

 breadth. Denuded test bright red, with patches of white more 

 numerous wirhin than between the poriferous zones. Test rather 

 flat, not stout, circular, ^vith a rather small mouth distinctly- 

 depressed. Primary tubercles small and numerous ; only one row 

 in each vertical set of plates extends from pole to pole, but at and 

 below the ambitus each plate has a transverse row of four or five 

 tubercles in the interambulacral and of two or three in the 

 ambulacral areas. There are about 27 primary tubercles in a row 

 in a specimen measuring 32 mm. in diameter. The anal area is 

 chiefly occupied by a few large plates ; the madreporite is of 

 proportionately large size, and the ' oculars ' are ordinarily shut 

 out from the edge of the anal space. The edge of the mouth is 

 deeply inflexed, and the cuts are wide but not very deep. In a 

 specimen in which the lantern of Aristotle was examined, the 

 teeth were found to project very little from the alveolus ; this was 

 stout and wide, with two deep grooves, and had the tooth connected 

 with it by a descending but not by an ascending process. The 



apophysis is almost straight. 



Diameter of 



Diam. Height. Calyp. area. Periproct. Peristome. 

 32 mm. 16 6-5 2-5 8-5 



Hab. Macclesfield Bank, between 30 and 44 fms. 



It is a somewhat difficult matter to suggest what are the nearest 

 allies of this species ; although the characters just enumerated 

 appear to be constant for the fairly large number of examples 

 which were collected, none of them are of large size, and, possibly, 

 better grown specimens will throw more Ught on this question. 



Teipneustes geatilla. 



Echinus gratilla, Linn. Syst. Nat. x. (1758) p. 664. 



Tripneustes gratilla, Loven, Bih. Svensk. Vet.-Akad. Hdlgr. xiii. 

 iv. no. 5 (1887) p. 77. 



An interesting young example of this species was taken in 



30-40 fms. ; its proportions are somewhat different to the smallest 



specimen 1 was able to measure some years since (see P. Z. S. 1879, 



p. 662). 



Percentage value of 



Absol. diam. Height. Abact. Anal Act. Porif. zone, 

 in miUim. system, sy.stem. system. 



28 69 23 12-5 30 8-2 



Lagaitum; DECAGoifALE. (Plate XXVI. figs. 4 & 5.) 



Scutdla decagonalis, de Bl. Diet. Sci. Nat., s. v. Scutella, p. 229. 



A fine series of this species, commencing with specimens less 



