86 Transactions of the i^'^Cl^^^lX^^' 



In variety h, two very distinct forms prevail in addition to tlie 

 usual arcuate type : the one (Plate XL!., Figs. 28, 29) bears a certain 

 resemblance to the form predominant in variety a, but the taproot- 

 like prolongation is here represented by a small fascicle of rootlets or 

 series of laminae whose axis is produced at right angles to the plane 

 on which the remaining ones subtend; this peculiarity of their 

 arrangement gives these spicula a very j^lant-like aspect. The re- 

 maining form (Plate XLI., Fig. 31) is easier figured than described ; 

 it seems, however, to be an extraordinary development of an irregular 

 echinate fusiform type, one end of which has become fasciculate, 

 while the other gives rise to a variable number of lacinulate pro- 

 longations; this inter^^retation is the more easily understood on 

 reference to the spicula of Acantliogorgia Grayi (Plate XLI., 

 Figs. 32, 33). Here, in addition to the slender arcuate form, irregular 

 echinate and more or less lacinulate fusiform spicula form the pre- 

 vailing type, some of these, moreover, evincing a tendency to 

 become fasciculate at one extremity. 



Paraniuricea intei'media and sjnnosa, Klk., and Villogorgia 

 nigrescens, Duch. et Mich., according to Kolliker, possess the generic 

 characters of the foregoing varieties of ]placomus, and are referred 

 by him to the same genus. 



Eunieea. — Polypary branching, axis corneous; sclerenchyma 

 of a suberose consistence, calices very prominent, cylindrical, the 

 apertures usually bilabiate. 



The characteristic form of the spicula in this genus is repre- 

 sented at Plate XLI., Figs. 34, 36. These for the most part consist 

 of large, handsome, evenly tuberculate fusiform spicula of various 

 colours, and mclude the form usually prepared for sale, referred to at 

 the commencement of this paper : these spicula occupy the deeper 

 part of the coenenchyma ; superficial to them is a cortical layer 

 of variously modified echinate or furcato-clavate spicula, of which 

 examples are shown at Plate XLI., Figs. 35, 37, 38. To this genus 

 should doubtlessly be referred Plexaura pinsilis and pendula, from 

 the Antilles, of Valenciennes, but to which two species no reference 

 is made by either ]\Iilne Edwards or Kolliker. The last-named author 

 substantiates the claim of Gorgonia suecmea, Esp., and Eunieea 

 clavaria, Lamouroux, to be ranked as true Euniceai. Milne Ed- 

 wards was not altogether certain of their true position. In addition, 

 Kolhker includes the following new species in the same genus : — 

 Eunieea liirta, Stromeyeri, fiisca, Sagoti, and luguhris, Duch. et 

 Mich., and E. mammosa, Lamouroux. Eunieea lilantaginea of 

 Milne Edwards has already been referred to the genus Muricea. 

 The spicula of Gorgonia 'pseiulo-antijpathes, Lamk. (non Esp.), essen- 

 tially follow the Eunicean type. 



Plexaura. — Polypary branching, axis corneous; ccenenchyma 

 extremely thick, of a suberose consistence ; calices not prominent. 



