128 Bvlletin Vanderbilt Marine Museum, Vol. VII 



outer margin undulate-convex, the lateral margins oblique and 

 the inner margin narrower than the outer. Farther down on the 

 arm, these plates appear to be nearly oval. The side arm plate 

 overlaps dorsally on either side of the base of the dorsal arm plate, 

 laterally supports six short spines that increase in length from 

 ventral to dorsal (see plate 44), and ventrally margins the under 

 arm plate. The four most ventral spines are finely serrulate, as 

 figured ; the fifth and sixth spines are thicker, longer and usually 

 not serrulate. There is one tentacle scale present ; this is a large 

 oval, one-half as wide as long, being as long as and adjacent to 

 the lateral margin of the octagonal ventral plate. The ventral arm 

 plate is lozenge shape, each plate being a not quite equal-sided 

 octagon. The external surface of the plates is finely granulose. 



References: Ophiactis hrocki, de Loriol, P., Revue Suisse de 

 ZooL, 1893, 1. 1, p. 401, pi. 14, figs. 1-a, e. — Clark, H. L., Mem. 

 Mus. Comp. ZooL, 1915, vol. XXV, p. 266, entry No. 775. 



Ophiactis savignyi (Muller and Troschel) 



Plate 45 



Type : Savigny published the first record of this species in the 

 exquisite figures given on plate 2, figures 4 and 5, Echinodermes, 

 Descripte de Egypte, 1809. His specimens were deposited in the 

 Paris Museum. Muller and Troschel gave the first text descrip- 

 tion of this species, which was apparently based on the Paris 

 Museum material, which was collected in Egypt. 



Distribution: This exquisite small tropicopolitan species, 

 originally reported from Egypt (1809), has since been recorded 

 from numerous stations in the littoral zone of the tropic Atlantic, 

 Indian and Pacific Oceans, as follows: Egypt (Ljungman), Red 

 Sea (Risso) ; Zanzibar (Lyman, H. L. Clark) ; Indian Ocean, 

 Mauritius (Ljungman, H. L. Clark) ; Ceylon (H. L. Clark) ; Nico- 

 bars (Lutken) ; Singapore (von Martens, H.L.Clark), Bat j en, Java 

 (von Martens) ; Dutch East Indies at twelve "Siboga" stations: 

 Java Reefs, Timor, Kwandang Bay, Gebe Isle, Saleyer, Aru Isles, 



