24 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



la. Aplidium sp. aff. lohatum Savigny 



Figures Ig-lc 

 MATERIiVL EXAMINED 



Marianas Islands, Saipan : P. E. Cloud, sta. E-7. A single colony, 15 mm.X 

 8 mm. in extent and 3 mm. in thickness, attached to coral rock (USNM 11506). 



Description'. — Test rather transparent, quite colorless, embedded 

 with white sand grains. Lacunar system complicated, can be seen 

 through test, clearly defined by absence of whitish sand grains as well 

 as by presence of brownish fecal pellets cast out along sides of lacunae. 

 Two common cloacal apertures on surface, one with simple margin, the 

 other with about 10 marginal lobules, surrounded by several small 

 patches of embedded sand grains (fig. 17t). Zooids usually brownish 

 in color. Postabdomen lost in most zooids. Length reaching about 

 3 mm. including postabdomen. Abdomen about two-thirds the length 

 of thorax, postabdomen nearly as long as thorax. Branchial aperture 

 6-lobed, atrial aperture opening at tip of a short siphon projecting 

 from level of third stigmatal row, with simple atrial languet at 

 anterior base of atrial siphon. About 10 strong longitudinal muscles 

 on each side of thorax. Stigmatal rows present 10 or 11; number of 

 stigmata could not be determined exactly because all zooids examined 

 were rather strongly contracted. Six large tentacles ( ? ) , dorsal 

 languets distinct. Anus opening at level of seventh transverse vessel. 

 Stomach situated approximately at middle of abdomen, elongated, 

 with 5 longitudinal folds including typhlosole. Proximal end of 

 rectum distinctly constricted from middle intestine and forms a pair 

 of inconspicuous caeca (fig. 1^) . No gonads seen in any postabdomens 

 dissected. 



Kemarks. — The lacunar system of the present colony seems to differ 

 from that of the typical Aplidium lohatum^ which consists of several 

 radiating canals converging on a common cloacal aperture. The 

 number of stigmatal rows, up to 11, seems to be too great for typical 

 A. lohatum^ though a form of this species, A. tremulum Savigny, is 

 figured as having 11 rows also. The zooids are ratlier small as com- 

 pared with those of typical forms. All these differences, however, 

 seem to be insufficient to separate the present specimen from A. lohatum 

 as a distinct form. 



2. Aplidium sp. aff. depressum Sluiter 



Figure 2 



Aplidium depressum Sluiter, 1909, p. 102, pi. 5, fig. 6. — Van Name, 1918, p. 167, fig. 

 115. 



^MATERIAL EXAMINED 



Philippine Islands, Baliwasan : W. R. Taylor, sta. 10 (jar 2). One small 

 colony, 5 mm. X 2 mm. in extent, attached to an alcyonarian coral (USNM 

 11660). 



