On the Type-specimens of Poeeilasma carinatum. 101 



XL1X. — The Type-specimens of Pcecilasma carinatum, lloek 

 (Cirripedia). By VV. T. Calman, JJ.S •. 



(Published by peruiissiuu of the Trustees of the British Museum.) 



In the Report on the Cirripedia of the c Challenger ' 

 Expedition, Hoek described two species of Pwcilasma 

 (/\ carinatum and P. gracile) differing from all timse referred 

 lo the genus by Darwin in having the sides of the carina 

 expanded below. Pilsbry, in 1U07, transferred these species 

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

 U ' lyptelasma, with M. subcarinatum } Pilsbry, as the type- 

 species. Annandale, more recently (lUlb), has transferred 

 Glyptelasma to Poecilasma, believing that the included species 

 have more affinity with that genus than with M< g dasnia. 



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

 and of the specimen described by Gruvel in 1U01 reveals 

 certain omissions and errors in the original descriptions which 

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

 but also the generic and sub-generic definitions. 



Megalasma (Glyptelasma) carinntum (llo k). 



Pcecil<ism« carinatum, Hoek, Rep. ' Ohallejiger' Ciiripedia, 1883, p. 1 1, 

 pi. i. figs. 8-10, pi. ii. 'fig. J, pi. vii. ligs. 6, 7 ; id. 'tiiboga ' Exp., 

 Cirripedia Pedunc. 1907, p. 5, pi. i. tig. 1 ; Uruvel, Trans. Linn. Sue. 

 London; Zool. viii. 1901, p. L57, pi. xvii. figs. 9-16. 



Megalasma (Glyptelasma) carinatum, Pilsbry, Bull. U.S. Nat. 31 us. lx. 

 1907, p. 93 ; 'id. Proc. Acad. Nat. Sci. Philadelphia, lix. 1907, p. 410. 



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

 mentions six specimens or this species. One, from Station 24, 

 off Culebra Island, is no longer in the collection. From 

 Station 344, off Ascension Island, he records ''Three speci- 

 mens and two very small ones." The bottle bearing the 

 label of this station now contains six specimens ranging from 

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

 these is represented by the capitular valves (the carina and 

 one scutum separated from the others) and by a partially 

 dissected body with ovigerous lamella? still attached. Since 

 the capitular length of this individual is that indicated by 

 11( ok for his largest specimen, and since it appears to have 

 furnished the material tor most of his figures and much of 

 his description, I have selected it as the holot) pe. 



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

 some difficult}-, lie says (Chall. Rep. p. 45) : — " Capitulum 



Ann. d; Mag. X. Hist. Ser. 9. Vol. i. 27 



