14 ASCIDIID^.. 



/. Languet. *• f. Connecting spurs of respiratory cavity. 



A. Heart. m. Mouth. 



n. Nucleus. o.p. Odd terminal processes on median line. 



g. t. Gemmiferous tube. /• 1>- Lateral processes of ventral side. 



m. b. Muscular bands. p- p- fnir of terminal processes of posterior 



c. c. Coecum of respiratory cavity. extremity. 



(Fig. 1.) Solitary form, from the dorsal side. 

 (Fig. 2.) Solitary form, seen from the ventral side. 

 (Fig. 3.) Solitary form, seen in profile. 

 (Fig. 4.) Three-quarter view of the aggregate form. 



(Fig. 5.) Part of chain oi Salpa Caboti, to show the arrangement and connection of the 

 components. 



Family ASCIDIIDtE. 



Body sacciform, gelatinous or coriaceous, fixed at one extrem- 

 ity, free at the other, witli two more or less prominent orifices, 

 a branchial and an anal ; branchial sac simple or plicate. Not 

 miited into groups by a common integument ; solitary or grega- 

 rious. Oviparous. Sexes miited. 



In the genera Ascidia and Molgula the gills are not plicated, 

 which is the case in the other genera. Cynthia and Chelijosoma 

 are sessile, while Boltenia and C//stiiig-ia are pedunculated. 



Ocnus BOLTENIA, Savigny. 1828. 



Body more or less globular, fixed, pedunculated ; test coria- 

 ceous ; orifices lateral, each cleft into four rays; branchial sac 

 longitudinally plicated, surmounted by a circle of compound ten- 

 tacula. 



Boltenia clavata. 



Plate XXIII. Fig. 325. 



Ascidia clavata, Fabricius, Fauna Groenl. 333 (1780). 



Ascidia (jlobifer a, Sabine, App. to Parry's Voy. No. 10 (1824). 



Boltenia reniformis, MacLeay, Lin. Tr. xiv. 536, pi. xviii. (1825). — Dujardin in La- 

 marck, An. sans Vert. iii. .539 (1840). — Gould, Invert. 319. — ?De Kay, N. Y. 

 Moll. 260, pi. xxxiv., fig. 234 (1843). — Stimpson, Grand Manan, 20 (1854). 



Boltenia clavata, Stimpsox, Smithsonian Check List, 1 (1860), no descr. 



'i Boltenia Bolteni, Packard, Invert, of Labr. in Mem. Bost. Soc. N. H. i. 277, no descr. ; 

 not fusiformis, Savigny. 



? Boltenia oviformis, Packard, Can. Nat. (1863). 



This is a most curious object, and greatly resembles in shape 

 the flower of Ladies'-slipper (^Cypripedium) on its stalk. It has 



