NO. 1 DICKINSON : SPONGES OF GULF OF CALIFORNIA 47 



ectosome and a drab endosome. The surface is superficially smooth. There 

 are oscules 2,500 fx in diameter. These are coronal and covered by a black 

 sieve net with openings 100 fi in diameter. 



There is a well-marked ectosome 1 mm thick, which may be detached 

 with difficulty. 



The gross endosomal structure is "bready" and confused. 



The principal spicules are oxeas 75 /a by 2,100 fx and calthrops 95 /x 

 by 410 /x. A few of the latter are only triradiates. Two smaller types of 

 oxeas are present. The first, 2 /a by 800 fi, is smooth. The second, 10 /x by 

 375 fi, is lumpy and gives the impression of having a series of small rings 

 around it throughout its length. There are also characteristic asters, 

 which average about 15 /x in length. 



Holotype. — AHF no. 26. 



Type locality. — Tepoca Bay, Mexico ; from the shore of a rocky reef. 



Distribution. — Same. 



Material examined. — 

 Sta. 1077-40 Tepoca Bay 2- 4-40 13 m 



Remarks. — Sphincter ella tricornis Wilson, 1904, from Panama seems 

 to be the nearest relative of this sponge. It, however, has very much 

 larger oxeas, 135 ;li by 5,000 /x, only the smaller size of triradiates, and 

 lacks the black net arrangement which is so striking a feature of the 

 Hancock sponge. 



Family PlakinastrellidaC de Laubenfels 

 Genus POEGILLASTRA Sollas 

 Poecillastra tenuilaminaris Sollas 

 Plate 93, Fig. 186 ; Plate 94, Fig. 187 



Normia tenuila?ninaris Sollas, 1880, p. 186. 

 Poecillastra tenuilaminaris Sollas, 1888, p. 85. 



Diagnosis. — This is a thin sponge, stiff, drab in alcohol, and smooth. 

 Typical spicule measurements are as follows : 



Calthrops (size of rays), 50 /x by 450 {x; oxeas, 3,870 fx by 60 /x; 

 plesiasters (greater length), 30 /x; metasters (greater length), 15 /x; 

 micoxeas, 3 /x by 145 /x. 



Holotype. — British Museum. 



Type locality. — Japan. 



Distribution. — This sponge has been found in southern California 

 near Santa Catalina Island as well as in Japan and the Gulf of California. 



Material examined. — This sponge was found in the Gulf of Cali- 

 fornia. Exact location is unknown. 



Remarks. — Spicules in this specimen are somewhat larger than is 

 typical. 



