NO. 1 DICKINSON : SPONGES OF GULF OF CALIFORNIA 11 



Oscules are also found. They vary in size up to 4,000 /a with an 

 average of 3,500 /x. The spiculation is, in general, tangent and reticulate. 

 The principal megascleres are exclusively diacts with an average size of 

 14 by 240 /a, and there is little variation from the average. A second 

 category of oxeas, averaging 3 by 130 [x, with very little size variation is 

 also present. 



Holotype. — AHF no. 3. 



Type locality. — East of San Marcos Island, Mexico; 12 fms; sand 

 bottom. 



Distribution. — Same. 



Alaterial examined. — 

 Sta. 581-36 San Marcos Island 3-14-36 24 m 



Remarks. — This Adocia differs from A. gellindra^ also found in the 

 Gulf, chiefly in the size of the principal oxeas, which are almost twice as 

 large, and in the possession of a second class of megascleres. In the latter 

 respect it is like A. neens^ a West Indian sponge, but A. neens has much 

 smaller spicules and has a protoplasmic mesh at the surface resembling 

 that found in Callyspongia. It might be added that the ramose shape and 

 drab color of the new species contrast with the lavender color and encrust- 

 ing form of A. gellindra. 



Genus PELLINA Schmidt 



Pellina semitubulose (Lieberkiihn) 



Plate 13, Figs. 25, 26 



Halichondria semitubulose Lieberkiihn, 1859, p. 363. 



Diagnosis. — The specimen is a paper-thin tube 3 or 4 mm in diameter 

 and 25 mm long. It is broken at one end. 



The ectosome is raised and easily detachable, since it covers subdermal 

 spaces. It contains tangentially placed spicules. The endosome has a well- 

 defined isodictyal reticulation. 



The sole kind of spicule is the smooth oxea. These are most frequently 

 5 by 130 fjL, but there is considerable range from 10 by 125 |ii to 2 by 50 ju,. 



Holo type. — Unknown. 



Type locality. — Mediterranean. 



Distribution. — Cosmopolitan. 



Material examined. — 

 Sta. 640-37 San Lorenzo Channel 3- 7-37 60 m 



Remarks. — The tube described above is beyond doubt an oscular 

 chimney broken from the basal mass, of which only fragments are left 

 along with the tube. 



