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BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



tentacles in the Siboga specimen of geornetrica showed that in that 

 form the order of succession is first canal, then tentacle. 



A second feature of difference is the presence of pigment spots or 

 ocelli in the Philippine specimen. No such structures were observed 

 by Maas in geornetrica. With future research it may prove thnt 

 either tentacles or canals may appear first, and that ocelli may be 

 either present or absent ; perhaps they were obscured by preservation 

 in the Siboga material. The question can not be settled until more 

 specimens are available, and therefore the identity of the present 

 example remains in doubt. 



CALYCOPSIS TYPA Fewkes, var. SIMULANS Bigelow. 



Plate 40, fig. 8 ; plate 41, fig. 1. 



Sibogita simulans Bigelow, 1909a, p. 213, pi. 5, figs. 4, 5; pi. 41, figs. 8, 9; 



pi. 43, figs. 1, 2.— Mayer, 1910, p. 187. 

 Calycopsis typa Vanhoffen, 1911, p. 214, pi. 22, fig. 6 (not Fewkes). 



Calycopsis typa variety simulans — material examined. 



The advanced condition of the gonads and canals shows that it is 

 nearer maturity than the small size, after preservation, would sug- 

 gest. 



Canals and tentacles. — There are 12 canals — 4 radial, 8 adradial. 

 Of the adradials, one ends blindly, the other seven join the cruciform 

 base of the manubrium (pi. 40, fig. 8) . Each of the radial canals and 

 six of the adradials are connected with large tentacles. Two of the 

 adradials, one being the blind one, are connected with small tentacles. 

 Obviously these two canals are the youngest ones. There are like- 

 wise eight small tentacles in connection with which no canals have 

 yet been developed. The tips of the large tentacles are all so much 

 damaged that the terminal knobs are entirely lost. In each of the 

 two eastern Pacific specimens there were 8 adradial canals, all blind. 



Manubrium and gonads. — The mouth is surrounded by a simple 

 cruciform lip without any trace of marginal folds or crenulations 

 (pi. 41, fig. 1). The gonads (pi. 41, fig. 1) are of the usual type, con- 

 sisting of double series of regular transverse folds in each inter- 

 radius, about 15 folds in each, the sexual development occupying 

 nearly the entire length of the manubrium. 



Color. — In the preserved condition the gonads are pale brownish- 

 vellow. There are no ocelli. 



