76 



CCELENTEEATA 



L. fragilis* Haeckel {Ascortis fragilis Haeck.). Color white or yel- 

 lowish ; spicules both straight or. somewhat arched and triradiate ; sep- 

 arate individuals 1 to 1.5 mm. long; colony 5 to 10 mm. in diameter: in 

 shallow water from Long Island Sound to Gulf of St. Lawrence; 

 common ; Europe. 



Order 2. HETEROC(ELA. 



Small sponges usually more or less cylindrical in form with thick 

 walls and a cloacal cavity lined with a flat epithelium and not with col- 

 lar cells, the latter being confined to more or less well-defined chambers 

 or in radial tubes which are joined by means of small inhalent dermal 

 canals with the outside; either solitary or colonial: 6 families and about 

 90 species. 



Family 1. GEANTIIDAE. 



Radial tubes extending outwards from the cloacal chamber; distinct 

 and continuous layer (dermal cortex) peripheral to the radial canals; no 



conspicuous quadriradial spicules lin- 

 ing cloacal cavity : about 13 genera and 

 40 species. 



1. Grantia Fleming. Triradial 

 spicules filling mesoglea and projecting 

 into cloacal cavity; cortex thin: 20 

 species. 



G. ciliata (Fabricius) (Fig. 136). 

 Solitary sponges, 12 mm. high and 3 

 mm. thick; 2 kinds of monaxial spic- 

 ules, a longer kind protecting the 

 osculum and a shorter in the cortex 

 protecting the inhalent canals: Rhode 

 Island to Greenland, from low water line to 60 fathoms; Europe; often 

 common. 



G. canadensis Lambe. Body 3 mm. high and 1 mm. thick: Gulf of 

 St. Lawrence and northerlv. 



Fig. 1.36 — (Irantia ciliata (Kellogg) 



A, group of 3 individuals ; B, 



longitudinal section. 



Family 2. LEUCONIDAE. 



Collar cells in spherical flagellate chambers from which branched, 

 exhalent canals extend to the cloacal cavity: 5 genera. 



Leucandra Haeckel. Spicules without regular arrangement: many 

 species. 



* See "On the Spongiae Ciliatae," etc., by II. J. Clark, Mem. Best. Soc. Nat. Hist., 

 Vol. 1, p. .305, 1866. 



