1112 ■ THE VOYAGE OF H.M.S. CHALLENGER. 



demonstrated by Biitschli (1882, loc. cit., p. 519). Some other species united by 

 Ehrenberg with Lithohotrys belong to other genera. The number of Lithobotryida 

 found in the " Radiolarian ooze " of the Challenger collection, is far greater than that of 

 the Cannobotryida and Pylobotryida. But only a small part of them could be 

 thoroughly examined and described here, so that their number may be greatly 

 augmented by further accurate researches. We here arrange those forms in four 

 genera, representing two different subfamilies. The terminal mouth of the thorax 

 remains open in the Botryopylida, whilst it becomes closed by a lattice-plate in the 

 Botryocellida. In each group there are shells with and without porous tubes. The 

 number of these tubes, and also the number of lobes of the cephalis, is very variable, 

 and may in future serve for the distinction of more genera. 



Synopsis of the Genera of Lithobotryida. 



I. Subfamily ( Cephalis without porous tubes, .... 488. Botryopyle. 



Botryopylida. ^, 



Mouth of the thorax open. ( Cephalis with a variable number of porovis tubes, . 489. Acrohotrys. 



■R t ll'rl ' Cephalis without porous tubes, .... 490. Botryocella. 



,,,.,, Cephalis ■with a variable number of porous tubes, . . 491. Lithohotrys. 



Genus 488. Botryopyle, Haeckel, 1881, Prodi'omu.s, p. 440. 



Definition. — L ithobotryida without tubes on the cephalis, and with the 

 mouth of the thorax open. 



The genus Botryopyle comprises the simplest forms of Lithobotryida, the lobate 

 cephalis bearing no tubes and the basal mouth of the thorax remaining open. It may 

 be derived either from Dictyocephalus or from Desmospyris, by development of lobes 

 on the cephalis and of an internal frontal septum, separating the larger occipital lobe from 

 the smaller frontal half of the shell. The latter may be divided again into anterior 

 frontal lobes, lateral buccal lobes, &c. 



1. Botryopyle sethocorys, n. sp. (PI. 96, fig. 7). 



Cephalis trilobate, separated by a deep collar constriction from the hemispherical thorax, which is 

 twice as broad. Occipital lobe helmet-shaped, little longer than the two hemispherical frontal lobes. 

 Surface spiny. Pores irregular, roundish, of very ditferent size. 



Dimension's. — Length of the shell O'l, breadth 0'07. 



Habitat. — Western Tropical Pacific, Station 225, depth 4475 fathoms. 



