PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVI. 



\ 



Fig. 1.— Cross-section of 

 TENTACLE OF Sagartitt 

 paguri; ec. Ectoderm; 

 p, Dark brownpigment 

 IN endoderm. 



428 . 



been 'hDaleOTange, in^^^n^t^^^^i^^^^^^'oloved above, brown below. 

 Tentacles pale, annulated with two or throe gray rings; inside blacR- 

 ish." In the present specimens the color is a uni- 

 form dark chocolate brown. In the endoderm of 

 the tentacles granules of dark brown pigment oc- 

 cur, arranged in a characteristic manner. They 

 form two streaks, varying in ])readth, situated 

 either one on each side of the median line of the 

 oral surface of the tentacle (fig. 1) or else along its 

 lateral surfaces, and they seem to vary somewhat 

 in breadth. This arrangement corresponds with 

 Verrill's statement as to the blackish coloration of 

 the inner surfaces of the 

 tentacles, but 1 was not 

 able todeterminethe ex- 

 istence of the gray rings which he mentions. 

 The base of the largest individual meas- 

 ured 2.3 cm. in diameter and the height of 

 the column (contracted) 0.5 cm. 



The ectoderm of the column wall is thin- 

 ner than the mesogkea, which on its outer 

 surface is raised into numerous horizontal 

 ridges. The circular musculature is rather 

 feeble, but the sphincter is strong and of 

 the form represented in fig. 2. The longi- 

 tudinal muscles of the tentacles are moder- 

 ately developed and are ectodermal in posi- 

 tion (fig. 1). 



The stomatodffium possesses two pairs of 

 but moderately developed siphonoglyphs. 

 The mesenteries are arranged hexamerously 

 in four cycles with, in some individuals, 

 occasional representatives of a fifth. The 

 first and second cycles are perfect. The 

 longitudinal muscles are well developed and 

 end abruptly at their inner edges, while ex- 

 ternally they taper gradually, the parieto- 

 basilars and basilars are feeble, and indeed 

 hardly noticeable. 



Reproductive elements were found only 

 on the mesenteries of the third and fourth 

 cycles. Acontia were present but were not 

 abundant. 



The habits of this form suggest its reference to the genus Adanisza, 

 but the arrangement of the mesenteries clearly indicates it as a mem- 

 ber of the SagartiiniB, and it is to be assigned to the genus Sagartia. 



Fig. 2.— Longitudinal section of 

 COLUMN WALL OF Sagartia jmguri, 

 showing sphincter muscles. 

 ec, Ectoderm, en, Endoderm. 



