1546 THE VOYAGE OF H.M.S. CHALLENGER. 



Dimensions. Diameter of the central capsule 015 to 0'25, of the nucleus 0'06 to 01, of the 

 calymma 0'8 to 1'2. 



Habitat. Mediterranean ; Portofino, near Genoa (Haeckel) ; Messina (Hertwig). 



2. Phceodina cannopylea, n. sp. 



Central capsule subspherical, scarcely depressed in the direction of the main axis. Astropyle 

 with a finely ribbed radiate operculum, about as broad as the radius of the capsule, prolonged into a 

 slender, tubular proboscis which is S-shaped, about as long as the radius, and similar to that of 

 Phceomlla primordialis, PI. 101, fig. 1. Parapylse also tubular, with two slender prolongations, half 

 as long and broad as the proboscis of the parapyle. Nucleus spheroidal, about half as broad as the 

 capsule. This species differs from the preceding mainly in the cylindrical slender prolongations of 

 the three apertures, which are similar to those of Aulosphcera and Aularia (PL 111, fig. 2). 



Dimensions. Diameter of the central capsule 0'2, of the nucleus 01, of the calymma 1/2 to 1/5. 



Habitat. Tropical Atlantic, Station 347, depth 2250 fathoms. 



Family LXXII. CANNORRHAPHIDA, Haeckel, 1879 (PI. 101, figs. 3-14 ; 



PI. 114, figs. 7-13). 



Cannorrhaphida, Haeckel, 1879, Sitzungsb. med.-nat. Gesollsch. Jena, Den. 12, p. 4. 



Definition. PH^EODARIA with an incomplete skeleton, composed of numerous separate, 

 not radially arranged pieces, which are either hollow tangential spicula or cap-shaped 

 dishes, or fenestrated rings, scattered loosely in the calymma. Central capsule placed 

 in the centre of the spherical calymma. 



The family Cannorrhaphida comprises those PH^EODARIA in which the incomplete 

 skeleton is represented by numerous separate pieces of silica, which exhibit very different 

 forms, and are scattered tangentially on the surface of the spherical calymma, sometimes 

 also throughout its jelly-mass. They agree in this peculiar character with the 

 Thalassosphserida (among the SPUMELLARIA) and bear the same relation to the skeleton- 

 less Phseodinida as the Thalassosphserida do to the Thalassicollida (compare pp. 10 and 

 29). The Cannorrhaphida represent the former group among the PH^EODARIA. They 

 differ from the following family, the Aulacanthida, in the arrangement and position of 

 the hollow spicula, which are never directed radially and never touch the central capsule, 

 as is constantly the case in the latter. 



Two genera of Cannorrhaphida have been hitherto known. The first species observed 

 in a complete and living state (at Messina in 1859) was Cannobelos cavispicula, described 

 in 1862 in my Monograph as Thalassoplancta cavispicula (foe. cit., p. 261, Taf. iii. 

 figs. 10-13). I there figured a complete living specimen with expanded pseudopodia and 

 a double central capsule (in the stage of self-division). The latter was surrounded by an 



