Watt.- — On Boltenia pachydermatina. 



347 



Herdman's " Eeport on Tunicata, ' Challenger ' Expedition," 

 vol. vi. First of all, as to the position of the heart, Herdman 

 speaks of Culcolus as being singular among the Cynthiidse in 

 having the heart on the right side of the body, in close rela- 

 tion to the endostyle : as we have seen, in Boltenia pachy- 

 dermatina it occupies this position. Secondly, in the branchial 

 sac Boltenia 2^ctc]iydermatina alone of the BoltenicR possesses 

 six folds on each side, the others having more : in Culeolus 

 six appears to be the normal number. 



Again, Culcolus and Boltenia pachydermatina agree pretty 

 closely in the structure and position of the gonads, also in the 

 fact that the ripe ova are enclosed in capsules of cells. In 

 both Boltenia pachydermatina and Culeolus we find sixteen 

 tentacles, placed larger and smaller alternating, and besides 

 these a number of smaller tentacles without definite arrange- 

 ment. 



The chief works which I consulted in waiting this paper 

 were, — 



Herdman's " Eeport on the Tunicata collected during the 

 Voyage of the 'Challenger'" ("Eeport on the Scientific 

 Eesults of the Exploring Voyage of H.M.S. 'Challenger:' 

 Zoology," vol. vi.). 



Hancock "On the Anatomy and Physiology of the Tuni- 

 cata" (Linnsean Society's Journal of Zoology, vol. ix., p. 309). 



Papers by Julin and van Beneden in the " Archives de 

 Biologic," tome ii., fascicules 1, 2 ; tome vi., fascicule 2. 



Bronn's " Klassen und Ordnungen des Thierreichs," iii., 1 

 (Malacozoa) . 



KEY TO PLATES XXXI.-XXXIV. 



a. 

 at. 



at. n. 



br. 

 br. f. 



bi-. n. 



d.b.v. 



d.g. 

 d.t. 

 d.v. 



en. 

 /,/• 



Anus. 



Atrial aperture. 



Nerves arising from the 

 atrial end of the ganglion. 



Branchial (oral) aperture. 



Longitudinal folds in bran- 

 chial sac. 



Nerves arising from the 

 branchial end of the 

 ganglion. 



Vessel running along the 

 dorsal free edge of the 

 branchial sac. 



Digestive gland. 



Dorsal tubercle. 



Vessel arising from the dor- 

 sal end of the heart. 



Endost3'le. 



Folds in test. 



Hermaphrodite genital 

 masses. 



g.d.I. 



g.d.r. 



h. 



i. 



i.s. 



m.b. 



n.g. 



03. 



03. a. 



r.t.v. 



St. 

 St'. 



t. 

 t.p. 



t'. 



tn. 

 r.v. 



Left genital duct. 

 -Right genital duct. 

 Heart. 

 Intestine. 



Structures on intestine. 

 ]\Iuscular bands in mantle. 

 Nerve-ganglion, 

 ffisophagus. 

 Oesophageal aperture. 

 Vessel to test from right 



side. 

 Stomach. 

 Stalk. 

 Test. 

 Processes on test, spinous, 



round, or oblopg. 

 Typhlosole in intestine. 

 Tentacles. 

 Vessel from ventral end of 



heart. 



