4 



25. Breynia vredenhurgi^ an undescribed Echinoid 



from the Indian Ocean. 



By Major A. R. S. Anderson, I.M.S., B.A., C.M.Z.S. 



(With Plate V). 



Genus BREYNIA, Desor. 



■_ 



Two fascicles abactinally, interaal as in Lovenia^ and peripe- 

 talons. Large abactinal tubercles onlj within the peripetalous 

 fasciole. Scrobicnles not internally prominent. A snbanal fasci- 

 cle. Apical system as in Lovenia ( Desor and Agassiz, Ann. des Sou 

 NaL 3eme serie, Zool., 1847. Vol viii., p. 12, and Vol. vi. PI. 

 16, fig. 14). 



BREYNIA VREDENBURGI, n. sp. 



1907. Bregma spec. nov. Vredenburg, Becords Geological 

 Survey of India, xxxir., pages 275, 284 



The main features of this species are ; a fairly large test 

 resting on a spot anterior to the mouth and on the posterior 

 part of the keeled sternum, ovoid in outline, gently arched abacti- 

 nally, flat actinally ; vertex behind the apical system ; an oblique 

 truncation behind ; a slight groove in front for the odd ambula- 

 crum ; internal, peripetalous and subanal fascicles ; an anteriorly 

 excentric apical system constituted like that of Breynia austra- 

 lasiae ; abactinal primary tubercles with deeply sunk scrobicules ; 

 the pores of the paired ambulacra almost obliterated within the 

 internal fasciole ; the actinal, broad, bare, posterior interambulacral 

 areas bounding a triangular sternum ; a long narrow labrum ; an 

 anterioily excentric and semilunar peristome mostly formed by 

 ambulacral plates ; and an elliptical periproct sunk in the posterior 

 truncation. 



The single specimen obtained from Port Blair, Andamans, 

 and now in the Indian Museum, measures 39 mm. in length, 31 

 mm. in breadth and 21 mm. in height : the apical system is only 

 12 mm distant from the anterior margin, and a few mm. behind 

 this is situated the vertex. 



In profile the anterior margin rises steeply from the ambitus 

 and then curves quickly backwards to the apical system. 



The paired ambulacra are very similar in shape to those 

 figured by Agassiz and Desor in A^m. Set. Nat. 3 erne Serie. Zool, 



vi. (1846) PI. 16, fig. 14. The anterior pair are almost trans- 

 verse, the poriferous zones fairly close together throughout 

 their course, not forming the wide triangular interporiferous 

 space of B. audralasifB shown by A. Agasaiz in III. Gat, Mm. 

 Oomp. Zool., No. vii., PL xv a., tig. 7 ; they are widest at the 4th 



