dredged up from the Gulf of Manaar. 49 



Halichondrina. 



Halichondria aceratosjriculum, n. sp. 

 (PI. V. fig. 19, a-d.) 



There was only a minute trace of this, but sufficient for 

 mounting and for the following description of its spicules, 

 which consist of four forms, viz. : — 1, acerate, fusiform, 

 curved, sharp-pointed, thickly spined throughout, 25 by 1^- 

 6000th (PI. V. fig. 19, a) ; 2, smooth, acerate, fusiform, 

 curved, slightly inflated in the centre, and gradually pointed, 

 35 by l-6000th (fig. 19, b) ; 3, bihamate, simple, 8-6000ths 

 long (fig. 19, c) ; 4, equianchorate, shaft slightly curved, 

 arms linear in appearance, and distinct when viewed laterally, 

 3£-6000ths long (fig. 19, d). 



Obs. This is evidently the spiculation of a variety of Hali- 

 chondria incrustans, in which the flesh-spicules, viz. nos. 3 

 and 4, are in form identical, while the acerate forms of the 

 larger spicules respectively lead to the designation. 



Esperina. 

 Esperia tunicata, Sdt. 



This consists of a thin fragment, about \ an inch in hori- 

 zontal diameter, abounding with the usual Esperian rosettes, 

 composed of the inequianchorate of the species, accompanied 

 by a great number of nondescript forms, which appear to be 

 half-developed inequianchorates that have respectively been 

 generated in separate cells. 



Esperia serratohamata, n. sp. (PI. V. fig. 20, a-d.) 



Of this sponge, which I have long wished to find, viz. since 

 I published a representation of the peculiar form of the biha- 

 mate found among the spicules in one of the chambers of 

 a specimen of Carpenteria balaniformis (' Annals,' 1876, 

 vol. xvii. pi. xiii. fig. 10), a minute portion has grown on 

 one of the Melobesian nodules, which has yielded sufficient 

 for mounting and retaining in the dried state respectively. 

 It possesses four forms of spicules, viz. : — 1, the usual Espe- 

 rian skeleton-spicule, smooth, fusiform, sub-pinlike, with 

 oval inflation at the blunt end, 43 by l±-6000th (PL V. 

 fig. 20, a) ; 2, large, bihamate, serrated on the outside towards 

 each extremity, witli the teeth directed backwards, 24 by 

 l£-6000th (fig. 20, b) ; 3, tricurvate, simple, hair-like, dis- 

 persed and in groups, 12-6000ths long (fig. 20, c) ; 4, in- 

 equianchorate, small, with the head nearly two thirds of 

 the entire length, 4 by 2i-6000ths (fig. 20, d), dispersed 



Ann. & Mag. N. Hist. Ser. 5. Vol. vi. 4 



