MOLLUSCOIDS. 



By a. E. Verhill. 



TUNIC AT A. 



Ascidiopsis complanata Venill. 



Ascidia complanata Fabk., Fauna Gionlandica, j). 332, 1780. — Verrill, Amer. 



Jouru. Sci. i, p. 93, 1871, lig. 11. 

 Ascidia callosa Stimpson, luvert. of Grand Manan, p. 19, 1853. 

 Ascidiopnh complanata Yerrill, Amer. Journ. Sci. iii, p. 289, pi. viii, f. 8, 1872. 



Some of the young specimeus are translucent pale olive; others are 

 older, with a dark olive-brown, thicker, and rougher test. It appears 

 to be the most common species. It is broadly attached by one side, 

 obliquely, and both tubes are on the upper side, near one end. They 

 are both short and broad. 



Lot No. 235, Penny Harbor, Cumberland Gulf, at low- water, Octo- 

 ber 4, 1877. No. 592, head of Cumberhmd Gulf, attached to roots 

 of kelp. May 19, 1878. No. 595, Cumberland Gulf, May, 1878. No. CGI, 

 head of Cumberland Gulf, on gravel beach, June 1, 1878. 



Halocynthia Verrill — Cynthia Savignj- (non Fabr., 1808). 



The name Cynthia having been x>reoccupied, and no other tenable 

 name having been given to the group, I propose to substitute Halo- 

 cynthia for the typical section of Savigny's genus, characterized by the 

 square apertures, compound tentacular appendages of the mantle, and 

 the development of two ovaries. The other subdivisions established 

 by Savigny appear to be of generic value, in the modern sense. 



Halocynthia rustica Yerrill. 



Ascidia rusiica Lixxii. — Fabuicius, Fauna Grijulaudica, p. :!;50, 1780,2Ja''S. 

 Ascidia monoeeros Moller, Kroyer's Naturhist. Tidssk., vol. iv, p. 95, 1842. 

 Ascidia condylomata Packard, Mem. Boston Soc. Nat. Hist., i, p. 277, 1867. 

 Cynthia monoccrox Yerrill, Amer. Journ. Sci., vol. i, j*. 93, 1871. 



Distinguished by tlie irregular, unequal warts and tubercles of the 

 surface, the larger ones mostly situated above the middle, and by the 

 more or less lu-ominent subconical tubercle at the summit, between the 

 bases of the tubes. Tliis terminal tubercle is often surmounted by sev- 

 eral hard chitinous points, and in the young a similar point often occurs 



147 



