ON THE SHETLAND CRUSTACEA, TUN1CATA, ETC. 315 



three or four tubercles much larger than the rest, the central one being 

 only slightly larger than the lateral. 



Jlrissopsis lyrifera (Forbes) = Brissus lyrifer, Forbes, British Starfishes, 

 p. 187, Brissopsis lyrifera, Sars, Oversigt af Norges Echinodermer, 

 p. 96. On the Unst and Whalsey Skerries Haafs ; also in St. Magnus 

 Bay. 



Echinocardium cordatum (Pennant) =Amphidotus cordatus, Forbes, British 

 Starfishes, p. 190, = Echinocardium cordatum, Gray, List Brit. Anim. in 

 Brit. Mus. Radiated Animals, p. 6. Only two or three specimens ob- 

 served, probably because our dredging was almost wholly confined to 

 deep water. 



pennatifidum, Norman, =Amphidotus gibbosus, Barrett, Ann. Nat. Hist. 



2nd ser. vol. xix. (1857), p. 33, pi. vii. fig. 2 (but not A. gibbosus of 

 Agassiz) . 



This species is certainly not A. gibbosus of Agassiz. It is widely 

 different from E. cordatum, but closely allied to A. ovatum, than which 

 it is much larger and different in many particulars. The name I pro- 

 pose for it is in allusion to the beautiful pennatifid pedicellarise with 

 which it is furnished, and which are wholly unlike those of E. ovatum. 

 The specimen procured by Barrett was " dredged in 25 fathoms on the 

 south side of Bressay Island, Shetland, on a coarse sandy bottom." I 

 have myself seen three specimens of the species from as many different 

 localities, one dredged by myself in 1867 in St. Magnus Bay, Shetland, 

 another procured by Mr. D. Robertson in the Clyde district, and the third 

 obtained by Mr. Hodge off the Northumberland coast. 



- ovatum (Leske)=A / mphidotus roseus, Forbes, British Starfishes, p. 196. 

 Very common in deep water, 40-140 fathoms. 



Spatangus purpureus (MUller). Common in deep water, down to 100 fa- 

 thoms. 



.1 meridionals, Risso, Hist. Nat. de 1'Europe Meridionale, vol. v. (1826) 

 p. 280 ; Sars, Middlehavets Littoral Fauna (1857), p. 118. 



Very near to S. purpureus, but the shell much higher and more 

 tumid dorsally, and the hinder portion more produced and narrower in 

 comparison with the anterior extremity. The colour is much deeper, 

 being of a very deep purple hue in every part ; the larger spines of the 

 interambulacral areas are not conspicuously larger and longer than the 

 rest ; the ambulacral fascioles are very narrowly lanceolate, four and a 

 half to six times as long as broad, and thus much longer in proportion to 

 their breadth than in S. purpureus, in which they are from twice and a half 

 to thrice and a half or, very rarely, four times as long as broad *. The 

 following give the respective dimensions of the parts in two specimens 

 of the same length : 



Fascicle Fascicle 

 Long. Wide. High. long. wide. 



inches. inches. inches. inch. inch. 



S. meridionalis 3| .... 3 T % .... 2-jL .... 1^- .... -f^ 



S. purpureus 3J 3^ 1-JL 1^- .... ^ 



The specimens measured were selected at random from a number, merely 

 as being of exactly the same length, and thus calculated to give a fair 

 idea of the specific differences. 



* These measurements are taken from one of the anterior fascioles ; and give the extreme 

 breadth and height to the outside edge of the pores. 



