122 Transactions of the Society. 



X. — Observations on Dactijlocalyx pumiceus (Stutchhury), with a 

 DescriiMon of a New Variety, Dactylocalyx Stutehhuryi. 



By W. J. SoLLAs, M.A., F.G.S., &c., &c. 



(^Eead 8fh January, 1879.) 



Plates V., VI., VII., and VIII. 



The specimens of Dactylocalyx which came under the examination 

 of Stutchhury were two, hoth of which belonged originally to the 

 Bristol Museum ; of these, one, a very fine and complete vasiform 

 example, is still preserved there intact ; of the other, which is the 

 describer's type, the Bristol Museum only possesses a part, the 

 other part, comprising a half of the originally vasiform specimen, 

 together with a piece broken from the remaining half, having been 

 exchanged with the British Museum for a half of a specimen of 

 Hyalonema japonica (Grey). 



Thus there now remains at Bristol a complete specimen of 

 Dactylocalyx, together with a fragment of the type, and having 

 had occasion, while arranging the collection of sponges in the 

 Museum, to examine this material anew, I came across some fresh 

 facts relating to it which appear to me worth recording. 



DESCRIPTION OF THE PLATES. 

 Plate V. 

 Fig. 1. — Dactijlocalyx pumiceus ; var. Stutchburyi. Lateral view. X 0"321. 

 Fig. 2. — The same, seen from above, x 0'3i. 



Plate VI. 



Fig. 1. — Dactylocalyx Stutehhuryi. Seen obliquely from below. X 0'37. 



Fig. 2. — A lantern-spine, supporting an acerate spicule; the ends of the 

 spicule are not represented in the drawing, x 50. 



Figs. 3 and 4. — Similar, but more usual form of lantern-spines, exhibiting 

 their ordinary reticulate character, x 50. 



Fig. 5. — Sexradiate spicule, from the surface of the perforating tubule in 

 D. Stutehhuryi. X 50. 



Fig. 6. — Quadriradiate spicules, common in the dermal layer of D. Stutehhuryi. 

 X 50. 



Plate VII. {Dactylocalyx pumiceus). 



Fir. 1. — Fusiform acerate spicule of the outer surface X 15; a, middle of 

 spicule X 150. 



Fig. 2. — Sexradiate dermal spicule with distal ray suppressed, x 50. 



Fig. 3. — Smaller acerate spicule, capitate at both ends, x 25. 



Fie. 4. — Sexradiate dermal spicule, with one of the liorizontal arms bent back- 

 wards, and all except the proximal ray with capitate ends, x 50. 



Fig. 5. — Typical sexradiate of the dermal layer, x 50. 



Fig. 6. — Sharply-spined fibre of the secondary netwoik. x 100. 



Fig. 7. — Secondary network formed on a framework of large sexradiate 

 spicules. X 50. 



Fig. 8. — Dermal sexradiate, with long, wavy, bianched rays, x 50. 



Fig. 9.— Small sexradiates, from the interior of the body-network; «, with 

 pointed, 6, with capitate ends. X 50. 



