70 PROCEEDINGS OF THE NATIONAL MUSEUM vol.81 



Very few of the large sigmas are found in the endosome. Ascending 

 fibers, lOOfi to SOOju, in diameter, cored by the styles. 



Principal spicules, subtylostyles (fig. 37, A) ; size, about 10/x by 

 410/i. First microscleres, giant serrated sigmas (fig. 37, B) ; length, 

 about 210/A to 265/1,, Second microscleres, sigmas (fig. 37, C) ; length, 

 about 40/x to 4:5(1. Third microscleres, palmate anisochelas (fig. 37, 

 D) ; often in rosettes; length, 32/^ to 38/a. Fourth microscleres, 

 palmate anisochelas (fig. 37, E) ; length, IQfi to 17 ix. 



Rema/rJcs. — Hentschel (1913) in his summary of the genus My cole 

 includes Paresperella (Dendy, 1905, p. 162, type species P. serrato- 

 ham-ata), but I hesitate to drop Dendy's genus without further 

 study. The size of the sigmas can not be used, it is true, for all 

 grades occur intermediate between the giant ones of Paresperella 

 and the typical small ones of Mycale., but the serration may be a 

 distinctive difference; and for the present, I propose to use it as 



Figure 37. — Paresperella psila de Laubenfels, X 300 



distinctive of Paresperella^ retaining this genus. The only sponge 

 having spicule measurements at all close to those of psila is My cole 

 fascifibula Topsent, 1904, from the Azores, but its megascleres are 

 polytylote. it has raphides, and its large sigmas not serrated. Lambe 

 (1894, p. 130) records a sponge from Vancouver Island, British 

 Columbia, as EspereUa serratohamata Carter, but it is quite distinct 

 fi'om psila and is not certainly correctly identified with Carter's 

 species. As compared to psila., it has much smaller (335/x,) mega- 

 scleres, smaller (157ju,) macrosigmas, lacks the smaller anisochelas, 

 and has toxas, which psila lacks. 



Genus ESPERIOPSIS Carter 



ESPERIOPSIS ORIGINALIS de Laubenfels 



Esperiopsis originalis de Laubenfels, 1930, p. 27. 



Holotype.—U.^.'^M. No. 21441 ; B.M, No. 29,8,22.54. 

 Type locality. — Pacific Grove, Calif., July 2, 1926, intertidal, col- 

 lected by me. The species is common in this vicinity. At first I 



