Spongida from New Brunswick. 91 



Genus Hindia. 



The body is free, without an involution of the texture, and 

 consists of a small central space occupied by spicules which 

 soon form a series of bifurcating, long, straight, radiating 

 canals, which open at the surface. The spicule element is 

 calcareous, more or less in the shape of a stemmed tripod, 

 with four limbs, and swollen or fringed at the ends, where 

 junction takes place in the others. 



The skeleton is remarkable for its regularity. 



Hindia sphceroidaliSj mini. 



The sponge-body is spheroidal. On the surface are pa- 

 pilliform eminences corresponding with the ends of canal- 

 spicules. Centrally the spicules are unattached, arc tri- 

 pod-stemmed in shape, with swollen extremities, and have 

 papillose limbs. Canal-system occupying much space; canals 

 straight, narrow, radiating, opening into their neighbours, and 

 formed by combinations of tetraclade spicules resembling those 

 of the central part, and very regular in shape and size. 



Locality. Lower Helderberg calcareous shale, New Bruns- 

 wick. 



EXPLANATION OF PLATE IX. 



Fig. 1. The figures thus marked are those of separate spicules, showing 

 their three- or four-limbed nature, occasionally expanded ends, 

 and the frequent irregular outline of one or more sides. 1. Soli- 

 tary spicide from the central space . 1 a. A group of united 

 spicules and others whose limbs are not quite in contact, from 

 the outer part of the central space. 



Fig. 2. Junction of limb-ends of different spicules (normal). 2 b. Junc- 

 tion of limb-end and side. 2 c. Expanded ends of limb. 2 d. 

 Junction of spicules in part of the canal-system : the frills are 

 shown in two instances in a side view and in one from above. 

 2 e. Junction of the limb-end of a spicule and the side of another. 



Fig. 3. The ragged semidenticulate appearance of one of the edges of a 

 spicule-limb. 3 a. From the outer part of the central space 

 tangential to some commencing canal-systems : showing the 

 irregular surface of the spicules, and the aborted junction ends. 



Fig. 4. The broad spiculate formation of the floor of a canal-system, and a 

 part of a side with included spaces leading to neighbouring 

 canals : this is a longitudinal or radial view. 4 a. Tangential 

 section of some canal-systems, not near the surface : they are 

 small systems ; and the dark limbs were united in the perfect fossil 

 with other elements. 4 b. The reticulation around the canal- 

 openings ju.st beneath an abraded surface. 4 c. The nodules 

 on the surface surrounding the openings of the canals or pores, 

 each nodule being a fourth limb to a spiculate element. 



Fig. 5. Part of a radial section, magnified. 



Fiq. <5. The body of the fossil, natural size. 



Fig. 7. PctlcBftcJilya penetrans^ Dune, within the skeleton, magnified. 



