LOVENIA ELONGATA. 575 



This species is more closely allied to the Japanese Lovenia than to L. 

 elongata ; it has a few characters recalling the latter. 



Guyaquil ; Gulf of California. 



Lovenia elongata 



! Spatangus elongatus Gray, 1845, Eyre Voyag., I. 

 \ Lovenia elongata Gray, 1851, Ann. Mag. N. H. 



[/;, is; PI. XXXVIII.. f. 27, 28. 

 PL XIX\ f.1-4 ; PI. XXV. f. 31 ; PI. XXVI f. 35, 36; PL XXXVII f. 



Test depressed, flat, pointedly heart-shaped from above ; edge of the test 

 angular ; anterior groove desp at the ambitus ; posterior interambulacral 

 space extended, truncated, bevelled inwardly. Greatest breadth between 

 the apical system and the anterior edge; genital openings close together ; 

 madreporic body small. Internal fasciole of uniform breadth, surrounding an 

 elongate, posteriorly pointed plastron, crossing the ambulacra at right angles, 

 slightly concave towards the apical system ; the odd ambulacral zones run 

 along the edge of the flat abactinal plastron, the anterior half of which is 

 covered on both sides of the odd ambulacrum by rows of secondary tubercles, 

 with sunken scrobicular circles on the posterior edge only, five to six in each 

 row, diverging from the anterior ambulacrum, which is flat, with a narrow 

 interporiferous space, covered by minute granulation (miliaries) in the centre, 

 while between the pores on the edge there are minute secondary tubercles 

 with flat scrobicular circles, similar to those covering the remainder of the in- 

 ternal plastron, but smaller. The anterior ambulacral petals are triangular ; 

 the anterior poriferous zones obliterated ; the posterior zones forming, with 

 the anterior zones of the posterior lateral ambulacra, a nearly confluent arc, 

 separated by a short space, formed by the narrow abactinal part of the 

 interambulacral space. 



The posterior petals are more elongate ; the posterior zones meet at the 

 posterior edge of the internal plastron, which extends a short distance 

 beyond the apical system. The poriferous zones of the lateral ambulacra 

 are slightly sunken ; the pores vertically distant ; the zones are continued to 

 the edge of the test, flush with the test, as pairs of small pores placed close 

 together. The anterior groove commences at the anterior edge of the abac- 

 tinal plastron ; the flat plastron extending below the fasciole along the sides 

 of the groove to form a flat keel. The abactinal part of the test, outside 

 the fasciole, is covered by minute, closely-packed, raised, secondary tubercles 



