394 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
but the readiness with which they usually break apart on dissecting 
the zooid shows that this does not necessarily indicate incomplete sepa- 
ration. The structure of the ovary is best made out in those zooids 
(as that shown in text-fig. 20) in which the eggs are still small. It is 
then seen to consist of a single series of eggs of different sizes, lying 
near the common sperm duct. The eggs at the posterior end of the 
series are the largest. Sometimes the ovary may form a prominent 
projection on the surface of the body, connected with the body by a 
somewhat constricted base. 
The close relationship of Diplosomoides dubium Hartmeyer, 1903, 
(or Lissoclimim diibium, as the writer would call it), to this species has 
already been alluded to. Indeed, the differences betw^een the two 
are all, as far as can be judged from Hartmeyer's description and 
figures, well within the limits of individual variation, except that in 
the European species the zooids measure 4 mm. long, about double 
the length of well expanded zooids of the American form, and certainly 
extraordinarily large for a member of the Didemnidae. Hartmeyer 
describes the testis as composed of five incompletely separated divi- 
sions, while L. aureiwi frequently has more divisions which are often, 
at least, completely separated. L. dnbium is found in the Spitzbergen 
region and off Franz Josef Land, in depths to 85 meters. The other 
species, Diplosomoidcs flavescens Redikorzew, 1907, which the writer 
would transfer to Lissoclinum, is distinguished by having but four 
divisions to the testis and extremely large (up to 0.4 mm.) blunt-rayed 
spicules. It is from the Arctic Ocean north of Siberia. 
Lissoclinum aureum is foimd from the Banks of Newfoundland to 
off the coast of Martha's Vineyard, Mass., both in shallow water and 
in depths to 100 fathoms. A muddy bottom seems to be preferred. 
The specimens having but a few spicules, or in some cases appar- 
ently none at all, are from these localities: 
Station 2699 (off Newfoundland, N. lat. 45° 04', W. long. 55° 23', 
72 fathoms, August 22, 188(3); Bay of Fundy; Eastport, Maine, and 
Casco Bay, Maine, in shallow water; Station 46 B (near Jeffrey's 
Ledge, N. lat. 43° 03', W. long. 70° 04', 51 fathoms, hard sandy mud, 
September 4, 1873); Stations 170 and 171 (ofi' Cape Ann, N. lat. 42° 
33', \Y. long. 69° 59', 90 fathoms, fine sandy mud and gravel, August 
24, 1878) ; Station 137 (off Cape Ann, N. lat. 42° 32.5', W. long. 70° 
23.5', 53 fathoms, rocks, drifting into soft mud, July 29, 1878); oft' 
Cape Ann, 48 fathoms; Station 21 1 (ofl" Cape Ann, N. lat. 42° 38', ^Y. 
