16 ASCIDIIDiE. 



Boltenia microcosmus. 



Plate XXIV. Fig. 338. 



Boltenia microcosmus, AtiASSiz, Pr. Am. Ass. Adv. Sc. ii. 159 (1850). 

 Boltenia microsoma, H. and A. Ad., Gcu. Rec. Moll. i. 594. 



Sac larger and rounder than in the species to which it has been 

 formerly referred. Chelsea Beach and Point Shirley, also George's 

 Banks. (^Agassiz.') 



The figure given on Plate XXIV, was drawn by Mr. Burkhardt 

 from the original specimen. It serves, therefore, to fix the species 

 and give us the following characteristics. The sac is of a deep 

 rusty red color; it is almost equally rounded at its two extremities, 

 so as very abruptly to join the stem ; the openings are like two 

 prominent warts, nearly sessile, equally inclined in a contrary di- 

 rection; the stem is uniformly stout, of a dirty iron color, eight 

 inches long ; sac, one and six tenths inches long, eight tenths of 

 an inch wide. 



Boltenia Burkhardti. 



Plati: XXIV. Fig. 327. 

 Boltenia Burkhardti, Agassiz, in manuscript. 



Body angularly ovate, truncated anteriorly, posteriorly rapidly 

 and angularly attenuated to its stalk ; uniforndy covered with 

 short, stout cilia ; of a bright pinkish color, shading into yellow- 

 ish on its posterior half; orifices of a darker pink, or reddish, 

 connected by a long, horizontal, rectilinear elevation, from the ends 

 of which they open laterally ; stalk stout, three times the length 

 of the body, uniformly hirsute, yellowish. Body, one and two 

 tenths inches ; stalk, three and five tenths inches. 



The above description is drawn from a figure by Mr. Burkhardt 

 of a living Boltenia in the Aquarial Garden at Boston, 1859. The 

 species differs from any other yet noticed on our coast by the pe- 

 culiar angular shape of the body, the position of the orifices on an 

 elongated, horizontal ridge, and by its hirsute surface. Boltenia 

 ciliata of Mijller* is a much smaller species. 



* B. ciliata. Corpore sulM-eiiiformi, fusco-luteo, tnbercnhxto, ciliato ; orificiis jirominii- 

 lis, rubicundis ; pedunculo granuluto, ciliato, terminali ; L. totiiis animalis 18'" R. (Ind. 

 Moll. Gr. 22.) 



