Report on the zoological collections made in the Indo-Pacific Ocean ...

ECHINO DERM ATA. 151specimen measurin2: 46 millira. in length has a greatest width of2i) and a greatest depth of 15 millim. The dorsal surface slopesgraduallj- to the two sides, which are marked off from the ventralsurface by the development along the lateral line of from three to sixshort, conical, sharp denticle-like processes. From the median dorsalline to this line the scattered suckers increase in number ; they are,however, much more numerous on the ventral surface, and more regularityof distribution is to be observed along the ventral median linethan in any other part. The suckers are provided with stout plates,but no special terminal plate was detected. The calcareous plates inthe skin are on the general plan of those in S. unisemita ; but the barsdo not appear to be so stout, and there may be at least seven pores.The ten pieces of the calcareous ring are all equal, and the retractormuscles are not especially strongly developed. As in ^S^. unisemitathere is, comparatively, a feeble development of the digestive andrespiratory organs ; but these characters, as well as the stiffness ofthe tentacles, are rather points of generic importance.A more complete generic diagnosis will be made when the twospecies have been carefully compared.Two young specimens have the integument much thinner.Port Jackson, 0-5 fms., where it is, as otlior collections show,exceedingly common. Also fi-om North Dunbar Island, China seas,and from between Ball's Head and Goat Island (coll. Brazier) ; andtwo dried specimens, purchased in 1848 of Mr, Cuming, from BrisbaneWater, N. S. W.In the definition of the genus given by Prof. Selenka there occurthe words " Korper mit einfachen Fiisschen bedeckt, die in derrechten (oder linken) Flanke in einer Doppelreihe stehen " and;the presence of this more distinct set of suckers is implied in thespecific term of the American species, unisemita. In the presentspecies, of which there is a good supply of specimens, I observe thatthe double row occupies the middle of the trivium, but that itvaries considerably in the extent to which it isSome modification of the generic diagnosis must therefore lie made,and the suckers be spoken of as scattered over the body, but havinga tendency to form a regular double row in some part of thetrivium *.distinctlj^ developed.Seirvper, Hoi. p. 73.15. Stichopus variegatus.A single, rather small specimen from Port Molle.* Since working out this species I have had the opportunity of examininganother member of the genus from Kurrachee ;for 8. murrayi see Proc. Zool.See. 1883, p. 61.Mr. Ramsay tells me that the naturalists of Sydney have been in tlio habit ofregarding ^S. validum as the Holothuria spinosa of Quoy and Gaimard : thisdetermination cannot, I think, be accepted.