ON THE DEVELOPMENT OP TUBULIPOEA. 87 



'^ small purple Eschara," the form which is now com- 

 monly known as Idmonea serpens. The purple colour and 

 the parallel arrangement of the zooscia are expressly men- 

 tioned. The figures e and e on pi. xxvii represent the species 

 as growing on a substance which is doubtless the stem of the 

 "sickle coralline" (Hydrallmania falcata), as appears 

 from the description, on p. 75, of the Cellepora shown on 

 the same stem. The occurrence on this species of Hydroid is 

 eminently characteristic of the "small purple Eschara.''^ 



In 1766 (33, pp. 248,249) Pallas described the same species 

 under the name of Millepora liliacea, referring to EUis^s 

 description and figures; and it is given as Millepora tubu- 

 losa in the well-known work of Ellis and Solander (10, p. 136). 



In the enlarged thirteenth edition of the ' Systema Naturse ' 

 (1788) Gmelin complicates the question by describing the 

 species under no less than three diflferent names.^ The first 

 of these (torn, i, part 6, p. 3754) is Tubulipora serpens. 

 Linnaeus's diagnosis is repeated, but a reference to former 

 editions of the * Systema^ is omitted, while the small purple 

 Eschara of Ellis, and Millepora liliacea of Pallas are 

 given as synonyms. The second (p. 3790) is Millepora 

 tubulosa, Ell. and Sol., the small purple Eschara of Ellis 

 appearing a second time as a synonym. The third (p. 3790) 

 is Millepora liliacea, Pall., and Tubulipora serpens, 

 Linn., is given as a synonym. 



It appears to me that the Linnaean name must be rejected, and, 

 following the ordinary laws of priority, that the choice must lie 

 between Tubulipora liliacea. Pall. (1766), and T. tubulosa. 

 Ell. and Sol. (1788) . If the tenth edition of the ' Systema Na- 

 turEe' is adopted as the commencement of the binomial system, 

 Pallas's name has the right to be accepted ; while the adoption 

 of the twelfth edition as the starting-point would necessitate 

 the employment of T. tubulosa. Ell. and Sol. I shall follow 

 the example of Mr. Hincks- in regarding as valid Pallas's 



' As has already been pointed out by Lamouroux (25), p. 66. 

 ' See bis remarks on Flustra securifrons, Pall., on p. 122 of the 

 'British Marine Polyzoa' (1880). 



