REPORT ON THE RADIOLARIA. 1107 



apophyses may be lost by reduction. I have never observed Botryodea with more 

 than five apophyses. 



The Central Capsule of the Botryodea is not yet sufficiently known, no living 

 species having been observed. In some preparations from specimens in the Challenger 

 collections, stained by Dr. John Murray with carmine immediately after the dredging 

 operation, single Botryodea are to be found in which the central capsule is deeply 

 coloured. In Botryopera quinqueloba (PI. 96, fig. 2) it filled up the greater part 

 of the cephalis and seemed to be divided into some small lobes. In Lithohotrys 

 sphcBrothorax (PI. 96, fig. 15) it was divided into four lobes, three of which filled 

 the ti'ilobed cephalis, the fourth large lobe occupying a great part of the spherical 

 thorax. Details of their structure, unfortunately, were not recognisable. There can, 

 however, be no doubt that they are the same as in all other Nassellaria. 



Synopsis of the Families of Botryodea. 



1. Shell monothalamous, consisting of the loLate cephalis only, . . .1. Cannobotrtida. 



2. Shell dithalanious, composed of a lobate cephalis and a simple thorax, . . 2. Lithobotryida. 



3. Shell trithalamous, composed of a lobate cephalis, a thorax and an abdomen, . 3. Pylobotrtida. 



Family LVI. Cannobotkyida, Haeckel {sensu emendato). 



Cannobotryida, Haeckel, 1881, Prodromus, p. 440. 



Definition. — Botryodea monothalamia, the shell of which represents a lobate cephalis, 

 without thorax and abdomen. 



The family C a n n o 1> o t r y i d a (retained here with a stricter definition than originally 

 was given in my Prodromus) comprises those Botryodea, in which the whole shell is 

 represented by the cephalis alone, u-ithout thorax and abdomen. Since the two latter 

 joints, found in the two following families, are secondary productions, the Cannobotryida 

 must be regarded as the ancestral forms of all B o t r y o d e a, in an ontogenetic as well 

 as in a phylogenetic sense. 



Two species only of this family have been hitherto known, incompletely described 

 by Ehrenberg as Lithohotrys triloba and Lithohotrys quadriloha. A great number of 

 similar forms are to be found in the Radiolarian ooze of the Central Pacific, but they 

 are very minute, and difficult to examine. We can describe here only twelve species 

 of these, w^hich w^e arrange in two genera ; Botryopera without porous tubes, and 

 Cannohotrys bearing a variable number of porous cylindrical tubes (one to five). The 

 number of lobes of the cephalis is also variable in each genus (one to five or more). If 

 in the future these minute and interesting shells should be better examined, it would 



