MOI.LUSUA — IIHDhKV. 



343 



exciivalioii. Tliis scar is probably owiiij,' ratiior to arrested 

 development at a point surruuiulod l)y normal ■,'ro\vtli, than to the 

 actual removal of matter. 



In an erratic group like these 

 commensals, it is diHicult to 

 .seize on features of specific 

 discrimination. Judging from 

 literature, /'. sii//asteris appears 

 to differ by its denticulate colu- 

 mella and buried apex from 

 others of the genus ; some 

 weight may attach to the 

 difference of the host. 



The host lends its colour to 

 the commensal, and there is a 

 probability that different Pedi- 

 cularia may be confined to different hosts. P. sicula, Swainson, 

 is said by Philippi* to be attached to GoraUium rubrum. P. 

 japonica, DalL, occurs on Gurc/onia.f According to the same 

 author, I P. dwussnta, Gould, lives on Madrepora, as does an 

 unnamed species figured by Dr. J. D. Macdonald.§ Mrs. J.Gr. 

 Waterhouse, of Sydne}'', has shovi^n me examples of P. paci/iGa, 

 Pease, from Niue, Central Pacific, attached to Distichopora 

 coccinea, Gray, a host already named by Schmeltz.|] 



Fig. 70. 



Famibj STRUTHIOLARIID^. 



STRUTHIOLARIA, Lamarck. 



STRUTHIOLARIA SCUTULATA, Martyn, sp. 



Buccinum sciitulatum, Martyn, Univ. Conch., i., 1789, pi. 55. 



Struthiolaria sciUuIata, Tryon, Man. Conch., vii., 1885, p. 134, 

 pi. xii., f. 39, 40. 



Stations 28, 52. 



This species is the t3^pe of the genus Tylospira,^] a division 

 which appears to me hardly worth subgeneric rank. 



One specimen from 19-20 fathoms in the Shoalhaven Bight; 

 another from 22 fathoms off the Manning River. 



* Philippi— Moll. Sicil., i., 1844, p. 92. 

 t Dall.— Am. Journ. Conch., vii., 1871, p. 122. 

 + Dall.— Bull. Mus. Comp. Zool., xviii., 1889, p. 2.38. 

 § Macdonald — Trans. Linn. Soc. , xxii. , 1856, p. 243. 

 II Schmeltz— Cat. Mus. Godeff., iv., 1874, p. 141. 

 IT Harris— Brit. Mus, Cat. Tert. Moll. Austr., 1897, p. 222. 



