CYNTHIA. 17 



Ocnus PERA, Stimpson. 1852. 



Body pyriform, adhering by a very small base ; test gelati- 

 nous ; orifices sessile, the branchial six-lobed, the anal four-lobed; 

 branchial sac plicated. 



Pera pellucida. 



Pera pellucida, Stimpson, Proc. Bost. Soc. iv. 232 (1852) ; Check Lists, I. 



Body pear-shaped, the tunic at base often continued into a short 

 stem. Test rather thin, hyaline, covered with small conical emi- 

 nences or papillas, especially about the orifices, which are very 

 small, distant from each other, and difficult to distinguish. Bran- 

 chial sac with ten folds. Length, one inch. 



Found adhering to bunches of Sertularia polyzonias^ taken on 

 St. George's Bank in thirty Mhoms. (^Stimpson.} 



Oemis CYIVTIIIA, Savigny. 1827. 



Body sessile, covered with a coriaceous tunic ; oral and anal 

 orifices fonr-lobed ; branchial sac longitudinally plicated, sur- 

 mounted by a circle of tentacular filaments ; meshes of respira- 

 tory tissue not furnished with papillge. Ovaries usually two. 



The species range from low water to thirty fathoms. They are 

 frequently found associated in groups of numerous individuals, and 

 their tests, even in the same species, are often variously colored. 



Cynthia pyriformis. 



Plate XXIII. Figs. 320, 321. 



Ci/nthia jv/riformis, "Rathke. — Stimpson, Inv. of Gr. Man. 20 (18.')4) ; Check Lists, 1. — 

 Packard, Invert, of Labrador in Mem. Bost. Soc. i. 277 (1867), no desci-. 



This species I have identified by European examples sent me 

 by M. Sars. They are perfectly the same. It is one of the most 

 beautiful marine productions found in this region, having, in its 

 hard, velvety surface, and bright pink blush, precisely the aspect 

 of a blood-peach. In fact, it is called sea-peach by the inhabitants. 

 Some of my specimens are three inches in length. It lives in clear 

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