220 ECHINODERMA OF THE INDIAN MuSEUM, PART VH. 



PACHYLOMETRA ROBUSTA. 



Antedon lobusta 1888. P. H. Carpenter, " Challenger " Reports, vol. 26, Zoo- 

 logy, p. 220, pi. xliv, fig. I. 



Pachylometi't ri>hi(.sla I9i)9. A. H. Clark, Proc. Biol. Soc. VVasliiiigton, vol. 22, 

 p. 21. 



Habitat. — Ki Islands. 

 Depth. — 140 fathoms. 



PACHYLOMETRA SMITHI. 



Charitometni foiiit/ii 19i>8. A. H. Clark, Smiths. Misoell. Coll. (Quarterly Issue), 



vol. 52, part 2, p. 227. 

 Parhipnniftyd sniitJii 1909. A. H. Clark, Proc. Biol. Soc. Washuigton, vol. 22, 



p. 21. 



Habitat. — Philippine Islands. 



Depth. — 200-375 fathoms. 



PACHYLOMETRA INVENUSTA. 



Pachylometrainvenusta 1909. A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 



p. 149. 



Description. — This species is in general similar to P. i/i(icileiitfi, but differs 

 in manj' details. 



Cirri XXIII, 20-21, 30 mm. to 34 mm. long, ratlier slender, like those of P. 

 macilenta\ the proportions of the component segments are the same as in that 

 species, but the distal edges of the segments are slightly more tliickened, giving 

 the cirri as a whole a somewhat rougher appearance. 



Twelve arms (in the type) 17o mm. long, slender, as in P. iiiacilenta\ the 

 two IlBr series are 4 (3-|-4) ; the ornamentation of the IBr and IIBr series is 

 essentially as in P. nmcilenta: elements of the IBr series and f IBr series, first 

 two brachials exteriorly and first three interiorly, in close apposition and sharply 

 flattened laterally, the apposed edges somewhat everted ; brachials with the same 

 proportions as those of P.macilenta, but the proximal subquadrangular brachials 

 have the distal ends thickened and everted, and the remaining brachials have 

 rather prominently overlapping distal edges. The distal intcrsyzygial interval is 

 four or five oblique muscular articulations. 



The pinnules resemble tliose of P. niucileHta, but the genital pinnules are 

 somewhat more swollen than are those of that species. 



Tho colour in spirits is dull yellowish white. 



Locality.— 0/5^ SoidJi. Andanian. Island (11° 4(1' 30" X, lat.,9:! ](/ oo" !<:. 

 long.) 509 fathoiiis ; hnttuiti. leiiiperatwre Mf Fah7\ ; green mad and jvndiiinijcral 

 ooze. — One specimen. 



