90 ZOOLOGICAL COLLECTIONS MADE DURING [Jan. 4, 



nearly vertically ; below the ambitus and approaching the actino- 

 stome the rows become considerably flattened out and take on a 

 more horizontal direction. Test not thick, very nearly circular, a 

 good deal flattened; spines rather long, greenish, with (when dry) a 

 reddish purplish tip ; in each area there are two rows of primary 

 tubercles, of which the interambulacral are considerably the larger ; 

 in both sets the diminution in size on the actinal surface is very 

 rapid and very marked ; a row of small tubercles, separating the two 

 rows of primary tubercles, extends from the actinostome to some 

 way above the ambitus, in the ambulacral area ; there are but few 

 secondary tubercles, on each coronal plate ; and as the plates are high, 

 there is no appearance of crowding. The poriferous zones are of a 

 greenish-grey colour, and the two inner or upper pairs of pores 

 are placed at a httle distance from the outer or lower six pairs of 

 pores ; the spaces between the primary tubercles of the ambulacral 

 area are of a reddish colour. 



The actinostome is moderately large ; but there are no deep cuts, 

 and no large plates developed on the buccal membrane. As in S. 

 bullatus, the ridge connecting the auricles is exceedingly low ; the 

 abactinal system is comparatively small, the number of anal plates 

 not small ; the madreporic is not much larger than the genital 

 plates. As in S. bullatus, none of the ocular plates reaches the anal 

 area. I cannot say whether the presence of short white spinous 

 tubercles rising up so as to form a kind of anal tube is an individual 

 })eculiarity of the specimen under description. 



The following are the more important measurements : — 



Diameter of 



Diameter Height actiuo- abactinal anal Ambul. Interamb. Length 

 of test. of test. stonie. system, system. area. area. of spine. 



c)9 21 13 "8-5 5 9 lla 22 



One specimen. Tom Bay, 0-30 fms. ; bottom, sand, kelp, and 

 mud. 



Echinus magellanicus (Philippi). 



E. magellanicus, Pliilippi, Archiv fiir Naturg. xxiii. p. 130 

 (1857). 



Two species of the genus Echinus have been recorded from the 

 Striiits of Magellan, E. magellanicus and E. margarituceus. With- 

 out entering into any general discussion of their peculiarities, it will 

 be sufficient to point out (in consequence of the somewhat contra- 

 dictory statements that have been put out regarding them) that 

 E. magellanicus can be readily distinguished by its larger number 

 of primary tubercles. No specimens of E. margarituceus were ob- 

 tained in this collection. Those of E. mayellunicus are all small 

 in size. They were taken at : — 



(1) Tom liav. 



(2) Cockle Cove. 



(3) Trinidad Channel. 



