20 ASCIDIID^. 



spiniiles, the larger ones stout and curved, with l^hxck tips. Apex 

 of the test high, rising up between the two orifices into a square, 

 truncate, corneous projection, and terminating in five or six large 

 spines. Incurrent and excurrent orifices, consisting of four tri- 

 angular depressed valves, being surrounded by a raised broad rim 

 of crowded tubercles, surmounted by spinules. Length, half an 

 inch. A still larger specimen, over an inch in length, from the 

 Banks of Newfoundland, is in the Museum of the Essex Institute. 

 This species may be easily recognized by its conical form, with 

 circles of large wart-like tubercles, and the steeple-like corneous 

 apex, truncated at tip, and armed with acute, short, thick spinules. 

 Caribou Island, eight fathoms, on nullipores. (^Packard.) 

 The specimens figured were preserved in alcohol by Dr. Pack- 

 ard. The species must be nearly related to Ascidia monoceros* 



Cynthia rugosa. 



Ascidia rugosa, Agassiz, Proc. Am. Ass. Adv. Sc. ii. 159 (1850). 



Surface wavy, brown ; aperture square, of purple color. {Ag-assiz.^ 



I have seen no specimen or drawing of this species, and can add 



nothing to the description copied above. The "square aperture" 



suggests that the species belongs to tlie genus Ci/nthia rather than 



Ascidia. In the latter genus neither of the apertures is square. 



Cyntliia liirsuta. 



Plate XXIV. Fig. 336. 

 Ascidia hirsntn, Agassiz, Proc. Am. Ass. Adv. Sc. ii. 159 (1850). 



Still smaller (than Ascidia carnea}, of a rose color dotted with 

 white ; of an intense red around the square apertures ; the body 

 is covered with fringes. Off Cape Cod. {Ag-nssiz.} 



The figure referred to is copied from Mr. Burkhardt's beautiful 

 drawing of the original specimen. It serves accurately to fix the 

 species, which is of a correct egg shape. Its four-lobed orifices 

 place it in the genus Cyntlda. 



Professor Agassiz gives no measurements. I believe the draw- 

 ing to be twice the natural size of the animal. 



* A. monoceros. Cor])orc cylindrico ; tunica tubcrculata, pallide rnl)ra, prominentia, 

 cornea, conica, terminali, inter oriticia eminente instructa; oriticiis prominentibus, rubris. 

 L. 15"' lis. (Ind. Moll. Gr. 22.) 



