NO. 5 CLARK : ECHINI OF WARMER EASTERN PACIFIC 317 



none are conspicuously large but many are larger than the tubercles of the 

 interradi'al areas. Anterior lateral petals similar in general tuberculation 

 but the great breadth of the poriferous zones is very striking; the petals 

 are 9 mm wide and the interporiferous area is only 3 mm. There are 8-10 

 (or even more) tubercles in each series across the poriferous area. Anterior 

 unpaired petal is similar to the other petals but is perhaps a trifle narrower. 

 Abactinal surface densely covered with spines of which those covering 

 the interporiferous part of each of the paired petals are 2 or 3 mm long. 

 This series of long spines forks at the distal end of the petal and continues 

 to the test margin. Between petals 1 and 2 (as well as between 4 and 5 

 and 1 and 5) there are 2 parallel series of long spines running to the disk 

 margin, where all spines are 3 or even 4 mm long. This belt of long spines 

 forms the outer margin of the disk. Orally, the primary spines are 3-5 mm 

 long, cinnamon buff to light purple drab in color and contrast decidedly 

 with the dark purple drab of the disk. Pedicellariae very numerous, chiefly 

 minute ophicephalous^ or triphyllous, crowded among the spines. Color of 

 bare test dark purple drab; of the spine coat, light brownish drab. 



There are 7 adult specimens of this Dendraster, of which 2 are more 

 or less cinnamon brown while the other 5 are of varying shades of purple 

 drab. The latter, including the holotj'pe, are from San Rosario Bay, west 

 coast of Lower California, in 15 fms. The other 2 and 13 very young 

 individuals, 11-16 mm across, are from Lagoon Head Anchorage, west 

 coast of Lower California, in 7 fms. The rough appearance of the posterior 

 part of the dorsal surface, due to the long spines in radiating series (much 

 as in rugosus) is a notable feature of this species but is not as important 

 as the character and appearance of the petals on the cleaned test. 



Type. — Holotype, AHF no. 49, 4 paratypes. 



Type locality. — Station 610-37, Rosario Bay, Lower California, 15 

 fms, Februar}^ 28, 1937. 



Distribution. — West coast of Lower California from Rosario Bay to 

 Lagoon Head Anchorage. 



Depth. — 7-15 fms. 



Specimens exmnined. — The type, paratypes and 15 specimens from 2 

 stations. 



9 It is regrettable that Clark gives no information about these ophicephalous 

 pedicellariae otherwise found only in Echinodiscus and (young) Astriclypcus 

 among Scutellids. It would have been particularly interesting to learn whether 

 they are bivalved as the other pedicellariae, bivalved ophicephalous pedicellariae 

 being otherwise a very great rarity. In a couple of specimens of this species, a 

 young one and a fine adult specimen, sent me by Prof. McCulloch, I do not find a 

 single ophicephalous pedicellaria. 



