EEPORT ON THE MONAXONIDA. S3 



those of Esperiopsis chaUengeri proper. Length (in the lamella) up to about 0-63 mm.; 

 breadth usually about 0'015 mm. In the fragment of stem the megasclera are 

 much stouter, measuring about O'G by 0-025 mm. A few spicules of the stouter kind 

 also occur in the lamella, their presence being apparently due to the breaking up and 

 branching of the supporting stem ; this shows that the fragments of lamella and stem 

 probal:)ly belong to the same thing, (b) Microsdera ; palmate isochelse, large and 

 numerous, length about 0'05 mm. (often less, and sometimes up to 0'072 mm.). 



It will be seen that both microsdera and megasclera are considerably larger than in 

 the types of Esperiopsis chaUengeri. 



Locality.— Station 214, February 10, 1875 ; lat. 4° 33' N., long. 127° 6' E. ; east of 

 Meangis Island, south of Philippine Islands ; depth, 500 fathoms ; bottom, blue mud ; 

 bottom temperature, 41°'8. Fragments only. 



Esperiopsis profunda, Ridley and Dendy (PI. XIX. figs. 1, 1«, lb). 



1886. Esperiopsis profunda, Kidley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. 



p. 341. 



There are in the collection two deep-sea sponges which we unite under the above 

 name ; neither is in very good condition ; indeed the larger specimen is very imperfect and 

 hence our description of the external form is taken from the smaller. Sponge consisting 

 of a slender stem, composed of spiculo-fibre, expanded slightly below so as to form a 

 flattened base, and gradually dilating above into a narrow, tubular, elongated head ; we 

 have found no definite opening from the exterior into the central cavity of this head, but 

 the condition of the specimen does not warrant the assertion that none such exists. 

 Total height of sponge, 44 mm.* Longer diameter of tubular head (which in its 

 present condition is flattened) 4 mm.; diameter of stem near base 0'7 mm. Colour in 

 spirit light yellowish-grey. Texture very soft and spongy. Surface hispid. Dermal 

 'membrane, Oscula, and Pores unknown. 



Skeleton. — The skeleton of the head consists of a loose and confused reticulation of 

 long stylote spicules, derived from the breaking up of the stem, at the point where it 

 joins the head, into a number of thin, loose fibres, which radiate upwards through the 

 walls of the tube and are crossed irregularly by other stylote spicules. 



Sp>icules. — (a) Megasclera; of one kind only (PI. XIX. fig. 1), viz., very long, 

 rather slender and often very slightly curved, smooth styli, with evenly rounded base 

 (sometimes, however, becoming tylostylote), and tapering very gradually to a sharp point 

 at the apex; size about 1*4 by 0'0157 mm. (6) Microsdera; of one kind only, viz., 

 large, palmate isochelae (PL XIX. figs, la, lb), with almost straight shaft and rather 

 narrow front palm; these spicules may attain a length of 0'09 mm., but smaller ones 

 about 0"05 mm. long are much more common. 



' The larger specimen is a little over 100 mm. in height. 



