A. E. Yerrill on Ascidians from New Englamd. 



Art. XI.— Brief Contributions to Zoology from the Museum of 

 Tale College. No. X. — Descripthns of some imperfectly known 

 and new Ascidians from New England ; by A. E. Yeerill. 



Molgula Manhattensis Verrill. Figure 1, 



Natural History of Kevv York, 



, ^, „ .nvertebrata of Massachusetts, 'M 



ecL, p. 2j, isiu, (.copied from Dekay). 



Body somewliat oval, subglobular, or slightly cordate, iisuallj 

 somewhat compressed laterally ; when crowded often slightly 

 adhering together laterally ani more or less deformed ; usually 

 adhering to eel-grass {Zostera) and various sea-weeds, or to the 

 ^ under side of stones, by the left side, or obliquely 



#*v, ' /^ ^y *^® ^^S'^1 portioa The surface including the 

 ^r\ /' y tubes is generally thickly covered with fragments 

 \ V / of eel-grass, broken shells, particles of sand, and 

 various kinds of debris so as to entirely conceal 

 the surface and disguise the form ; sometimes, 

 however, in sandy regions the surface is nearly 

 destitute of such covering. The integument is 

 firm and thick, and w^hen clean it is translucent 

 and roughened throughout with minute, gi'an- 

 ule-like papillae, which are larger and more crowded on the 

 upper part and around the base of the tubes, where they 

 often form small, rough, unequal verrucae. The tubes originate 

 on the upper side, a little apart, the distance between usually 

 about equal to the diameter of the anal tube ;* they are both 

 rather long and diverge by curving outward from the base. 

 Ihe anal tube is smaller and somewhat longer than the branch- 

 ial usual y about equal in length to half the diameter of the 

 body, and tapers to the end, which is rounded and has a small 

 square aperture, its sides, near the end and often below, are 

 usually roughened by irregular, uneven papillre. The branchial 

 tube is shorter and stouter, widest at base, truncate at the end, 

 with SIX, small, obtuse, rounded papillae surrounding the orifice; 

 outside of these there are six, short, triangular lobes ; below 

 these there is often an irregular circle of about six to twelve 

 rougher papilla, alternately larger and smaller, and sometimes 

 other more irregular ones below, between the sulcations; these 

 are, however, sometimes wanting, as in the specimen figured. 

 In contraction the tubes form low, rough verruca, the anal 

 otten lour-lobed, both covered with rough, irregular papillse. 



i lie inner tunic, which is closely adherent to the outer, is 

 smooth, pellucid, light greenish, the dark intestine and a reddish 

 organ below it showing through. 



