112 UNITED STATES NATIONAL MUSEUM BULLETIN 251 



pairs of ampullae; two pigment flecks of sensory organ arranged 

 anteroposteriorly. 



Remarks. — The coloration and tlie surface appearance of the pres- 

 ent preserved specimen differ slightly from those of the specimens 

 previously described, which are generally yellowish brown and marked 

 with irregularly formed depressions on the surface. Such differences 

 are probably due to the unequal state of preservation. Two small 

 colonies from the Gilbert Islands (USNIM 11476, collected Aug. 27, 

 1951), found attached to the underside of a colony of Didemnum 

 {DideTrmum) candiduin Savigny, seem to represent young colonies 

 of the present species. They are respectively 12 mm. X 2 mm. and 

 4 mm. X 1.5 mm. in extent, extremely thin with zooids all laid hori- 

 zontally ; the smaller colony contains merely two zooids. The test is 

 transparent and contains a few sand grains and fecal pellets 

 within. Even larger zooids are only 2 mm. in length, while 

 most are strongly contracted to 0.5 mm. in length. Zooids are yel- 

 lowish brown. The thorax occupies one-third of the total length, 

 with about 8 longitudinal and about 30 extremely fine, transverse 

 muscles on each side. The exact number of stigmata in each of three 

 rows cannot be ascertained on examined zooids, although it is not great. 

 Two pairs of longitudinal muscular bands run along the abdomen. 

 The proximal end of the rectum is distinctly constricted from the 

 midintestinal portion, but does not form any caecum. The rectum 

 forms a remarkable crook in the posterior part of the abdomen and 

 this is the very important character upon which the present specimens 

 are identified as E. pyriforme. 



48. Eudistonia angolanum (Michaelsen) 



Figure 39 



Polycitor paesslerioides var. anrjolanns Michaelsen, 1914, p. 430. 

 PolycUor ampins Hartmeyer, 1919, p. 10.5, pi. 2, figs. 54-55. 

 Eudistoma angolanum Hastings, 1931, p. 86, fig. 9. 



MATERIAL EXAMINED 



Maeianas Islands: Saipan ; P. E. Cloud, sta. D-7. One colony (USNM 

 11539).— Saipan; P. E. Cloud, sta. D-8. One colony (USNM 11572). 



GrLBEBT Islands: Onotoa Atoll; A. H. Banner, sta. B-8. Three colonies 

 (USNM 11517).— Onotoa Atoll; P. E. Cloud, sta. GOC-28. One colony (USNM 

 11516).— Onotoa Atoll; P. E. Cloud, sta. GOC-55. Three colonies (USNM 

 11478). 



Description-. — Seven colonies from the Gilbert Islands and two 

 from Saipan Island were examined. The largest colony is 40 mm. X 

 28 mm. in extent and 12 mm. in thickness; another large colony from 

 the Gilbert Islands (USKM 11516) consists of three cormidia, re- 

 spectively 20 mm. X 15 mm., 15 mm. X 8 mm., and 14 mm. X 11 mm. 

 in extent and 8 mm. in tliickness, of wliich 3-4 mm. constitute the 

 corona. The upper part of the colony or the corona is usually bluish 



