150 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



Atlantic Ocean off Rio Janeiro. He does not indicate the number 

 of specimens he had. The individuals were 20 mm. long. 



Apstein (1894, h and 1904) describes well-developed zooids, 1.5 

 mm. and 3 mm. long, still attached to the stolon of the parent, so 

 that the connection between the solitary and aggregated forms is 

 established. He reports (1906, h) numerous specimens from the 



collections of the Tiefsee Ex- 

 pedition, agreeing exactly with 

 those from the Plankton Expe- 

 dition. Dober (1912) figures an 

 individual from the Tiefsee col- 

 lections which is clearly the 

 same as Traustedt's original 

 form. Traustedt and Dober 

 both figure the ganglion and 

 eye as seen in surface view. 

 Our knowledge of the aggre- 

 gated zooid of the species multi- 

 tentaculata is thus considerable, 

 though not complete as to the 

 oral and atrial musculature. 



Dober's figure is here copied 

 (fig. 135) and also Apstein's 

 (1904) side view of a much 

 younger individual (fig. 136). 

 The index letters and figures 

 are mine and show *the ho- 

 mologies with other species. I 

 would call attention to the fact 

 that there are but two well 

 developed body muscles. The 

 first of these is evidently 

 double. The second is branched in the same way as is body muscle 

 IV in the solitary forms of this species and Traustedtia multiten- 

 t-aculata, form bicristafa. We seem, therefore, to have four body 

 muscles in the solitary form and three in the aggregated zooids. The 

 next posterior muscle corresponds to the one which in the solitary 

 individuals we interpreted as either a fifth body muscle or a basal 

 atrial sphincter. 



Neither Dober's nor Apstein's figure shows other atrial muscles 

 clearly enough for us to discuss them. 



Apstein shows a well developed intermediate muscle complete 

 across the dorsal surface. Dober shows what appears to be a double 

 intermediate muscle, the posterior portion reduced to a vestige at 

 the angle of the mouth, the anterior portion lying more dorsal and 



Fig. 135.— Transtedtia multitentaculata, aggre- 

 gated ZOOIP, DORSAL VIEW. X 4§ DIAMETERS. 



From Dober (1912). 



