134 ZOOLOGICAL COLLECTIONS MADK DURING [JaU. 4, 



diately interior to these and similarly arranged, and a gastral layer 

 of sagittal triradiates, the basal ray pointing away from the gastral 

 surface, which is covered with quadriradiates. Body-acerates straight, 

 tapering from centre to sharp points, external end flattened, knife- 

 like, with a central thicker longitudinal ridge, minutely roughened ; 

 size 1-25 by -06334 miUim. Fine linear spicules of lip smooth, 

 straight, size' about '3 by •00475. Triradiates smooth, external ones 

 irregular, angles about equal, all rays somewhat curved ; rays re- 

 spectively -1013 to -20 millim., -23 to -4, -32 to-45 in length by -019 

 to '022 in breadth; intermediate triradiates sagittal, angles equal or 

 oral angle about 130°; basal ray -4024 by -03167 millim. ; lateral rays 

 curved, '2724 by -03167 millim. ; gastral triradiates sagittal, oral angle 

 160°, proportions and shape of rays the same fis of intermediate 

 spicules. Quadriradiates, two sizes: (1) with characters of gastral 

 triradiate but with small straight apical ray ; (2) smaller, lateral rays 

 curved towards cloaca: sizes respectively, basal rays "38 by -03167 

 and -1267 by -0095 miUim. ; laterals -29 by -03167 and -1267 by 

 '0095 millim.; apical -0565 by -01267 and"-1267 by -0095 millim. 

 Ratio of thickness of stoutest acerate to stoutest triradiate 2:1. 



Examined. In spirit and l)y sections in balsam. 



Hab. Victoria Bank (off S.E. Brazil), 39 fathoms; bottom, coral. 



Obs. One specimen represents this species ; the mouth is not well 

 preserved. It is covered in places with a brown coating of degene- 

 rate tissue. It belongs to the same group of the genus as N. (As- 

 candra) echinoides, Hackel, from Java, which it resembles in its 

 flattened shape, and the form of the large acerate. But the largest 

 triradiates are more than twice the size of those of that species, and 

 two kinds of quadriradiate occur instead of one. 



Aphroceras sericatum, sp. n. (Plate XL fig. 5.) 

 {Aphroceras, Gray, P. Z. S. 1858, p. 113; Lencandra, Hackel, 

 Kalkschwiimme, ii. p. 110.) 



Sponge tubular, elongate ; tube of almost equal diameter from 

 the slightly fringed mouth to near the rounded basal end ; length 

 from 2 to 3 times as great as the maximum diameter. Canal-system 

 and spiculation that of Leucandra, Hackel. Wall about 1 millim. 

 thick, penetrated by long stout aeerates measuring 2 to 3 millims. 

 by '06 to -073 millim., smooth, sharply pointed, slightly thicker 

 proximally, projecting from surface. Mouth fringed by a number of 

 slender aeerates about -QXA millim. in diameter, smooth and straight. 

 Internal triradiates sagittal, rays smootii, tapering to sharp points, 

 slightly undulating, oral angle varying from 110' to 160°, lateral 

 angles equal, basal ray measuring from -355 to -52 by •019 to -032, 

 the laterals slightly smaller ; external triradiates with aboral lateral 

 generally only about half the length of the sagittal. Quadriradiates, 

 rays smooth, gently curved and sharply pointed, facial rays each 

 measuring from -18 to '25 by '0095 millim., apical ray from '16 

 to '2 by -0095 millim. Ratio of diameter of stout acerate to 

 maximum diameter of rays of triradiate between 2 and 3 ;1. Colour 

 (in spirit) white. 



