(.hi the Type-specimens of Pceeilasina carinatum. 1"! 



XLIX. — The Type-specimens of Pcecilasrna carinatum, lloek 

 ( ( irripedia). By \V. T. Calman, D.Sc. 



(Published by permission of the Trustees of the BritisL Museum.) 



L\ the lieport on the ('irripedia of the ' Clialleu 

 Expedition, Hoek described two speciea of Pwcilasma 

 (/'. carinalum and 1 J . gracile) differing from ail those rel 

 to the genus by Darwin in Laving tl of the carina 



expanded below. Pilsbry, in 1907, transferred these species 

 to Hock's genus Megalasma } placing them in a new subgenus, 

 Glyplelusma, with M. subcarinatum, Pilsbry, as the type- 

 species. Aunandale, more recently (LUlGj, has transferred 

 Glyptelasma to JPcecilasma, believing that the iuclu le 1 .-[ 

 have more affinity with that genus than with Mt-gdasm >. 



A re-examination of the type-specimens of F. carinatum 



ami of the specimen described by Gruvel in 1DU1 reveals 



certain omissions and errors in the original descriptions which 



rve to be noticed, since they affect not only the specific 



but also the generic ami subgeneric definitions. 



Megalasma [Glyptelasma) carinatum (Ho k). 



Peecilasma carinatum. II jer ' < !impedia, 1883, p. il, 



pi. i. ti_-. 8-10, pi. ii, fig. 1, pi. vii. tigs. 6, 7 j id. 'tsiboga' Exp., 

 Dirripedia Pedunc. 1907, p. 5, pi. i. tig. I : Uruvel, Trans. Linn. Sue. 

 London. Zool. viii. 1901, p. 157, pi. xvii. tigs. 9 



Megalasma (Glyptelasma) carinatum, Pilsbry, Bull. U.S. Nat. Mus. lx. 

 1907, p. 93 ; id. Proc. Acad. Nat. Sci. Philadelphia, li.v. 1907, p. 416. 



Material examined. — Hoek, in his 'Challenger' Report, 

 mentions six specimens of this species. One, tiom Station 24, 

 off Culebra Island, is no long< r in the collection. From 

 Station 314, off Ascension Island, he records " Three speci- 

 meus and two very small ones." Tlie battle bearing the 

 label of this station now contains six specimens ran gin 2 from 

 1*75 mm. to 14: mm. in length of capitulum. The largest of 

 these i.- represented by the capitular valves (the carina and 

 one scutum separated from the others) and by a partially 

 cted body with ovigerous lamellae .-till attached. Since 

 the capitular length ot this individual is that indicated by 

 II- ek tor his largest specimen, and since it appears to have 

 furnished the material for most of his figures and much of 

 his description, I have selected it as the holotype. 



With regard to Hoek's figure of the entire animal then- is 

 some difficulty. He says (Chall. Rep. p. 1" : — "Capitulum 



Ann. tb May. N. Hist. S< r. 0. Vol. i. 27 



