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AOL. 76 



number varies from 10 to 40 approximately) but also the size and 

 shape of the spindles are subject to strong variation. The shape 

 of the spindles strongly suggests those in Peltogaster, which have 

 been described by Delage (1886) and figured by the present author 

 (Boschma, 1928, fig. 3). The spindles have a more or less pointed 

 extremity; some are comparatively slender, others are thicker. The 

 length of the spindles, even of those of one retinaculum, varies from 

 15fx to 55/x. Barbs could not be found at the surface of the spindles, 

 but when studied with a high power their surface appears somewhat 



Figure 8.— Briarosaccus callosus, retinacula. a, Part of the internal cuticle with 



RETINACULA. X 45. b, C, AND d, THREE DIFFERENT RETINACULA. X 330 



granulated, but without definite excrescences such as occur on the 

 spindles of many Sacculinidae. The basal part of the spindles is 

 more or less narrowed, forming a kind of short stalk. 



LITERATURE CITED 



H. Boschma, 1927. Uber europaische Formen der Gattung SaccuUna. Zool. 



Jahrb., Abt. f. Syst., vol. 54. 

 , 1928. Rhizocephala of the North Atlantic Region. The Danish Ingolf 



Expedition, vol. 3, part 10. 

 Y. Delage, 1886. Sur le Systeme Nerveux et sur quelques autres points de 



rOrganisation du Peltogaster (Rathke). Arch. Zool. Exp. G4n., vol. 4. 



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