208 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



11527) ; sta. 12, one specimen (USNM 11524) ; ste. 13, one specimen (USNM 

 11526) ; sta. 14, one specimen (USNM 11525) ; sta. 15, one specimen (USNM 

 11523).— Vicinity of Amoy ; S. F. Light, coll. Ten specimens (USNM 11704). 



Marianas Islands : Saipan ; lagoon west of island, entrance to Tanapag 

 Harbor; P. E. Cloud, Loc. 2. One specimen 8 mm. in length (USNM 11507).— 

 Saipan ; lagoon west of island, 500 yards NNE. of Managaha Id. P. E. Cloud, 

 Loc. 4. Two specimens, 11 and 16 mm. in length (USNM 11505). — Saipan; 

 lagoon west of island ; Tanapag Harbor. P. E. Cloud, sta. D-8. One specimen. 

 9 mm. in length (USNM 11467) . 



Gilbert Islands : Onotoa Atoll. P. E. Cloud, sta. GOC-55. Two specimens 

 16 and 17 mm. in length (USNM 11493) . 



Australia : Port Jackson. North Pacific Exploring Expedition 1853-18.56. 

 William Stimpson, coll., sta. SH 142. One specimen 17 mm. in length (USNM 

 11759) , on Uerdmania momvs var. grandis (Heller) . 



Description. — There are 24 specimens in the material, 17 from 

 the coast of Amoy, China, 4 from Saipan Island of the Marianas 

 Islands, 2 from the Gilbert Islands, and 1 from Port Jackson, Aus- 

 tralia. As seen in the following descriptions, the Amoy specimens 

 differ from those from Saipan, the Gilbert Islands, and Port Jackson 

 in the appearance of the alimentary canal and the branchial tentacles. 

 It is therefore convenient to describe these two groups of specimens 

 separately at first, and then compare them with each other in detail. 



Specimens from Amoy. — Up to 40 mm. in length excluding siphons 

 and posterior extension of test in some specimens. Body roughly 

 oval in shape, attached to substratum by ventral (left ventral in some 

 specimens) or posteroventral side. Sometimes posterior part of test 

 extended as long as body proper, so that animal is attached to sub- 

 stratum by this extended part of test, or many rooty protuberances 

 issue from ventral side of animal and serve as attachment organs by 

 grasping sand grains. Some specimens attached side by side, form- 

 ing an aggregated mass. Both siphons prominent, reaching con- 

 siderable length in some specimens. Branchial siphon terminal or 

 subterminal, atrial situated near middle of dorsal side, both apertures 

 4-lobed. Test generally leathery and tough, thin, 0.5-1 mm. in thick- 

 ness on dorsal side, but up to 2 mm. at some thickened places on 

 ventral side; surface originally smooth, but irregularly wrinkled in 

 various degrees by contraction, especially remarkably at siphons; 

 holds a small amoimt of mud between the wrinkles or in the grooves, 

 or covered partly by hydrozoans or other organisms. Color of test 

 surface varies from pale yellowish brown to grayish brown, sometimes 

 with a reddish tint, that of section and inner surface whitish, with 

 pearly, pinkish or slightly purplish glistening. In a 30 mm. long 

 individual, test may be described as hard, cartilaginous rather than 

 leathery. Spinules on distal portion of inner surface of siphons 

 sharply pointed, 35;u, to 74/a (most frequently 60-65/x) in length with 

 basal scaly part of nearly same length as spinule proper. Mantle of 



