Mr. H.J. Carter on two new Species ofGumminea?. 19 



ternate and birotulate ; the former moderately large, and the 

 latter extremely minute. The biternate spicule consists of a 

 straight shaft and three arms given off at the union of the two 

 upper fourths of the former (fig. 3) ; shaft obtusely pointed 

 above (fig. 4, a), and finely pointed below (fig. 4, c) ; inflated in 

 the centre, and covered throughout with short, conical, vertical 

 spines, except between the inflation and the arms, where it is 

 smooth like the first part of the latter (fig. 4, b) . Arms three 

 in number, parting from the shaft at equal distances from each 

 other, and dividing respectively into three secondary arms, all of 

 which are on the same plane and nearly perpendicular to the 

 shaft ; secondary arms obtusely pointed and covered through- 

 out with short, vertical, conical spines (fig. 5, a, b). Central 

 canal evident in every part (fig. 4, d), showing that the origi- 

 nal design of the spicule was biternate, which is confirmed by 

 the smaller or younger forms being of the same kind, but with- 

 out spines, and the central inflation consequently more evident 

 (fig. 6, a) . Birotulate spicules extremely minute, consisting 

 of a straight shaft and four recurved arms at each end 

 (figs. 7 & 8, b). Distribution : The biternate spicule, besides 

 being plentifully scattered throughout the mass, is particularly 

 congregated towards the surface, where it forms a layer with 

 the arms horizontal, and the obtuse ends of the shafts, as before 

 stated, supporting the cuticula. The birotulate spicule, on 

 the other hand, although equally scattered through the mass, 

 appears to be congregated most about the surface of the excre- 

 tory canals, whose course can be thus traced by this accumu- 

 lation in specimens which have been dried under compression 

 and afterwards mounted in Canada balsam. Measurement : 

 Shaft of the biternate spicule 14-6000ths inch long ; diameter 

 of the head or arms 13-6000ths. Shaft of birotulate spicule 

 1 -5000th inch long ; other parts too minute for measurement. 

 Size of specimen, that of the mass of dead Lophohelia over 

 which the Corticium has grown. 



Hah. Marine, growing over various objects, imbedded or not 

 in deep-sea mud, as the case may be. 



hoc. Western entrance of the English Channel, about 

 48° 31' N. lat., and 10° 03' W. long., in 500 fathoms. 



Obs. As the spicules of this Gummina come nearest to those 

 of Corticium candelabrum, Sdt. (Die Spong. adriat. Meeres, 

 p. 42, Taf. iii. f. 25) and Cplicatum (Die Spong. Kiiste Algier. 

 p. 2, Taf. iii. f. 11), I have given it this generic name, with a 

 deep-sea designation. It occurs in the specimen mentioned, 

 and on a large piece of Pachastretta abyssi, Sdt. (also dredged 

 up by the 'Porcupine'), over part of which it has dragged itself, 

 enveloping everything in its course like an JEthalium. While 



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