140 Mr. H. J. Carter on Specimens 



this was a form of Dr. Bowerbank's Tethea muricata up to 

 the date above mentioned ; or if so, no one ever noticed it 

 publicly. Still it is equally evident that Tisiphonia— Dor- 

 villia is sufficiently different from Tethea muricata to re- 

 quire specific distinction ; at the same time that Tethea muri- 

 cata is not a species of Tethea, but one of Stelletta, as Schmidt 

 has made it from his examination of the Florida specimen. 



Furthermore, we find Dr. Bowerbank multiplying the 

 varieties of this sponge under the names Ecionemia compressa, 

 Hymeniacidon placentula, and Normania crassa respectively 

 (B. S. 1874, vol. iii.), all of which specimens (now in the 

 British Museum) I have had the opportunity of examining. 

 Hence, when we find the species (varieties) of a sponge so 

 numerous, it becomes necessary to make a group of them 

 under a specific name ; and as Sir Wyville Thomson's use of 

 " Tisiphonia " claims priority in this respect, I have applied 

 it generically to the species above described, and shall apply 

 it provisionally to the two following ones, merely observing 

 that, while I consider them all varieties, the human mind can 

 never remember them without specific distinction. Nature 

 does not require this aid. 



Tisiphonia annulata, n. sp. (provisional) . 

 (PI. V. fig. 28, a-d.) 



Massive, charged with the spicules of the species, without 

 apparent regularity. Colour white. Spicules of three forms, 

 viz. : — 1, quadriradiate, arms equal in size, radiating at equal 

 angles from a common centre, annulated throughout with 

 alternate inflations and depressions, the former microspined 

 and sometimes broken or incomplete in the annulation, arm 

 17 by H-1800ths (PI. V. fig. 28, a and d) ; 2, acerate, smooth, 

 fusiform, curved, 63 by l^-1800ths (fig. 28, b) ; 3, spini- 

 spirulate flesh-spicule, 3-6000ths long (fig. 28, c). Spicules 

 arranged confusedly in an areolated sarcode ; nos. 1 and 3 in 

 great abundance and of various sizes, the former below and 

 the latter above their stated measurements respectively. Size 

 of specimen about l-12th inch in diamenter. 



Hah. Marine. Growing on hard objects, in the present 

 instance among the minute detritus attached to the specimen 

 of Stelletta euastrum (PI. VII. fig. 42). 



hoc. Gulf of Manaar. 



Obs. This sponge was found growing in the place just 

 mentioned. The facies of the spiculation appears to me to be 

 that of a variety of Tisiphonia ; and if so, the quadriradiate 

 spicule is, with the exception of the annulation, like that given 

 by Dr. Bowerbank oft Normania crassa (B. S. vol. iii. pi. lxxxi. 



