232 



PERA, n. g. 



Body pyriform, adhering by a very small base. Test gelatin- 

 ous. Orifices sessile ; the branchial six-lobed, the anal four- 

 lobed. Branchial sac plicated. 



P. PELLUCiDA. Body pear-shaped, the tunic at base often 

 continued into a short stem. Test rather thin, hyaline, covered 

 with small conical eminences or papillae, especially about the 

 orifices, which are very small, distant from each other, and 

 difficult to distinguish. Branchial sac with ten folds. Length 

 one inch. 



Found adhering to bunches of Sertularia polyzonias, taken on 

 St. George's Bank in thirty fathoms. 



BOLTENIA. 



B. RUBRA. Body arcuated, slightly compressed laterally, and 

 tapering rather abruptly to the stem, which is slender, very hard 

 and granulated. Test very rugose, especially on the dorsal 

 surface, and of a deep red color. Anal aperture nearly sessile ; 

 branchial on a short tube which curves toward the stem. Total 

 length one foot ; length of the body one and three fourths 

 inches ; breadth seven eighths of an inch. 



This species lives attached to rocks in from two to fourteen 

 fathoms. I have found it in Massachusetts Bay, from Boston to 

 Cape Ann ; and also at Grand Manan, at the mouth of the Bay 

 of Fundy. 



Mr. Stimpson also remarked, that he vv^as engaged upon 

 a Monograph of the Tunicata of our coast, in which de- 

 tailed descriptions of the above genera and species would 

 be given, as well as of many others not here mentioned. 



Dr. C. T. Jackson gave a detailed account of the process 

 of Etherization as performed on a Puma belonging to 

 Mr. Alger, for the purpose of performing the operation of 

 cutting off its claws. 



