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



Thomson IlyaJonema toxeres, is distinguished by its remarkably strong, bow-shaped, 

 spindle-like spicules. 



In the same year, 1877, M. and J. Young^ reported on fossil remains from the 

 carboniferous strata of Cunningham Baidland, near Dairy in Ayrshire, which included not 

 only the liyalonema parallelum, M'Coy, already described by Siiss, but a second species, 

 Hyalonema smithii, Young and Young. Besides the long, straight, smooth, knitting- 

 needle-like spicules which Suss refers to in Hyalonema parallelum, the Youngs found 

 also short five-rayed and six-rayed spicules. 



Among the sponges which A. B. Meyer brought home from the Philippines and 

 New Guinea, and handed over to Bowerbank for description, there was a cup-shaped 

 specimen which Bowerbank^ briefly described in 1877, and in spite of the entirely 

 distinct form of the spicules identified as a Hyalonema from which the basal tuft had been 

 torn off. This he named Hyalonema anomalum,. Dr. A. B. Meyer had the kindness 

 to hand over to me at my request a portion of this same specimen belonging to the 

 Dresden Zoological Museum, and I have been able to convince myself that we have here 

 to deal not with a Hyalonema, but with a badly-preserved specimen of Crateromorpha 

 meyeri ; and with this the description given by Bowerbank himself agrees. 



In the abundant sponge material which was collected during the deep-sea expedition 

 by Agassiz and Pourtales in the Gulf of Mexico, and entrusted to Oscar Schmidt for 

 examination, this renowned spongiologist found only two specimens of Hyalonema} 

 The larger specimen consisted only of a torn off s^jicular tuft partly covered by a 

 crust of Palythoa. The other, which was distinctly smaller, was however completely 

 preserved, and bore a sieve-net over its upper extremity. The latter was identified by 

 0. Schmidt as Hyalonema sieholdii. 



In the Bay of Biscay, during the French expedition of the " Travailleur," a specimen 

 of Hyalonema lusitanicum was dredged, accoi'ding to Norman's* account, from a depth 

 of 600 fathoms. 



In the report by G. Armauer Hansen on the Sponges of the Norske Nordhavs 

 Expedition, a badly-preserved Hexactinellid is described and figured (1885). It was 

 obtained from a depth of 1081 fathoms, lat. 63° 17' N., long. 1° 27' W., on Biloculina 

 clay. Armauer fianscn had for examination {loc. cit., 'p. 19) " several specimens with 

 round hollow stems of somewhat variable thickness, measuring up to 3 cm. in length, and 

 surrounded at the one extremity by a very loose almost cotton-like substance." Since 

 I observe a discohexact among the siliceous spicules figured {loc. cit., pi. v. fig. 10), 

 and since " the stem is composed exclusively of spicules which are truncato-spinose at 

 both extremities," I can in no way agree wath Armauer Hansen's opinion that this 



' Ann. and Mag. Nat. Hist, ser. 4, vol. rs. p. 425. ^ Proc. Zool. Soc. Land., p. 461. 



2 O. Schmidt, Spongien des Meerbusens von Mexico, 1879 and 1880, p. 64. 

 * Ann. and Mag. Nat. Hist., ser. 5, vol. vi. p. 436. 



