20 ASCIDIID.E. 



spinulcs, the larger ones stout and curved, with black 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 tulicrclcs, surmounted by spinulcs. 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 spinulcs. 

 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 irwnoceros* 



Cynthia rugosa. 



Ascidia rur/osa, Agassiz, Proc. Am. Ass. Adv. Sc. ii. 150 (1850). 



Surface wavy, brown ; aperture square, of purple color. (Agassiz.^ 



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



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



suggests that the species belongs to the genus C/jnthia rather than 



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



Cynthia hirsuta. 



Plate XXIV. Fig. 33G. 

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



Still smaller (than Ascidia carnca^, 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-assiz.') 



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 Cynthia. 



Professor Agassiz gives no measurements. I believe the draw- 

 ing to be twice the natural size of the animal. 



* A. monocerns. Corporc cylindrico; tunica tnhorculata, pallide rubra, prominentia, 

 cornea, conica, terminali, inter orificia eminente instructa; oriticiis proraiiientibus, rubris. 

 L. 15"' Es. (lud. Moll. Gr. 22.) 



