4 Tun. 
VI. TUNICATA. 
Chordates, and the systematic position and relations of Salpa. He 
declares very emphatically against the views that the Vertebrata are 
derived from Annelids, and that the Tunicata are degenerate Verte- 
brates. 
B.— ANATOMY, Ere. 
Metcalf (18) describes the structure of a new species of Octacnemus, 
obtained by the “ Albatross,” off Patagonia, which differs in some respects 
from the “ Challenger ” forms examined by Moseley & Herdman. He 
finds that in this case the animals are not solitary, but are connected 
together by processes in chains, as in Salpa. Possibly the “ Albatross ” 
specimens are chain individuals, and the “ Challenger” ones solitary indi- 
viduals of the same species. 
Amy E. Watch am (32) describes and figures the variations in the dorsal 
tubercle of forty individuals of Ascidia virginea. There appear to be 
two simple forms of tubercle, and several variations from each of 
these. 
Hetcdman (11) gives some details of anatomy in regard to some of the 
British Simple Ascidians, such as Forlesella tessellata. 
Ritter (22) gives a detailed account of the structure of the various 
organs in a new species of Perophora from California. He shows that the 
cells of the test are derived from mesodermal cells which migrate through 
the ectoderm. 
Julin (14) gives an account of the reproductive organs of Styelopsis 
grossnlaria. 
Todako (29) describes the structure of the eyes in Salpce, both soli- 
tary and aggregated. He maintains the homology of the Salpa eyes with 
the pineal and lateral eyes of Vertebrates. Ho classifies Salpa: into 
Brochoenterata , Ortho enter ata, and Carioenterata , according as the intes- 
tine forms a loop, a straight line, or a spiral coil. 
One of the most important contributions of the year is W. K. B kooks’ 
work on Salpa — first in the form of preliminary notices in the Johns 
Hopkins University Circular (2, 3, 4), and then in his large, finely illus- 
trated monograph on the genus (5), in which he gives an account of the 
structure and development both of the sexual and of the asexual forms, 
along with a very full discussion of theoretical matters. 
Metcalf gives an account of the structure of the eyes, subneural 
gland, and central nervous system in Salpa, both in his paper in the 
Zool. Anz. (17), and also as an appendix to Brooks’ Monograph of the 
genus (5). He deals also with the homologies of the nervous system in 
other groups of the Tunicata. 
Newstead(20) discusses the perivisceral cavity of Ciona, and considers 
that it is not the primitive blastocoele, but is rather a modified and enlarged 
epicardium. He regards the stolons of Ciona as modified budding 
organs. 
