NO. 1 DICKINSON : SPONGES OF GULF OF CALIFORNIA 19 



Family Tedaniidae Ridley and Dendy 



Genus TEDANIA Gray 



Tedania nigrescens (Schmidt) 



Plate 26, Figs, 51, 52 



Reniera nigrescens Schmidt, 1862, p. 64. 

 Tedania nigrescens Gray, 1867, p. 495. 



Diagnosis. — Specimens of this sponge vary from massive to encrusting. 

 In alcohol the color varies from almost black to drab. Oscules up to 5 mm 

 in diameter are frequently present, although not always so. There is a 

 dermal layer about 50 p. thick and nondetachable, although some speci- 

 mens seem to lack the layer perhaps because of rough handling. As a rule, 

 the surface is smooth, though in some specimens it is broken by protuber- 

 ances especially around the oscules. 



Principal spicules in specimens from the Gulf are styles averaging 

 about 8 /i by 150 /a. Special dermal spicules are tylotes 4 /x by 200 /x. The 

 microscleres are the characteristic roughened rhaphids (onychaetes) 1 (i 

 to 2/i.by 140 [X. 



Holotype. — British Museum. 



Type locality. — Mediterranean. 



Distribution. — ^\^''orld wide. 



Materials examined. — 

 Sta. 598-36 Puerto Escondido 3-17-36 Shore 



Sta. 631-37 La Paz Bay 3-6-37 10 m 



Sta. 639-37 Espiritu Santo Island 3-7-37 10 m 



Sta. 650-37 San Francisco Island 3- 9-37 90 m 



Remarks. — Tedania nigrescens has been reported from James Island, 

 Galapagos, and Magdalena Bay, Mexico, collected on the Presidential 

 Cruise to these waters in 1938, and by the Hancock Pacific Expeditions 

 from Albemarle Island in the Galapagos ; also from Mexico and Central 

 America. 



Genus AGARNUS Gray 



Acarnus erithacus de Laubenfels 



Plate 27, Figs. 53, 54; Plate 28, Fig. 55 



Acarnus erithacus de Laubenfels, 1927, p. 258. 



Diagnosis. — This is a massive sponge, brilliant red in life and drab 

 when preserved. Its spiculation is described as follows: "Ectosomal 

 spicules, tylotes with heads microspined ; size 3 /x by 185 jit to 4 /i by 175 tx. 

 Interratitial spicules, cladotylotes, size 1 1 /a by 230 [x. Chords ?>5 {x. Cor- 

 ing spicules styles; size, 18 ju, by 345 |U, to 17 /x, by 425 p.; these are the 



