1915.] A. Oxa: The Tunicata of the Indian Museum. 3 
Molgulid was published in “ Zoologischer Anzeiger ’’, Vol. XLIII, No. I, in November 
1913. 
Molgula simulans, n. sp. 
(CP ness 1 and 2.) 
External Appearance.—The body is ovate, broad and rounded at the anterior 
end and somewhat tapering towards the posterior, the long axis being directed antero- 
posteriorly. It is compressed laterally, evidently in consequence of preservation. 
The apertures are sessile, not conspicuous ; they are situated at the dorsal and vent- 
ral edges of the anterior end, the distance between them being about one-fifth of the 
longitudinal circumference of the body. The animal is not attached. 
The surface of the body is regular and even, and is pretty smooth. There are, 
however, a large number of small papilla-like processes, corresponding no doubt to 
the delicate hairs of other Molgulids, scattered all over the surface. These are usual- 
ly short and almost conical, but in some places they are longer and may even be 
branched. On account of the adhering mud particles they appear as minute opaque 
dots on the surface of the otherwise transparent test. Here and there foraminiferan 
shells and broken sponge spicules are found attached to the external surface of the 
body. The colour of the animal preserved in alcohol is a light transparent grey. 
The dimensions of the three specimens are as follows : — 
Specimen. Entire animal. Internal body. 
No. I Io mm. X7 mm. 4 mm. X5 mm. 
No. 2 8 mm. X5 mm. 3 mm. X 3 5m. 
No. 3 7°5 nm. X5 mm. 3 mm. X 3 mm. 
The Test is thin, soft, gelatinous, and quite transparent. Between the papilla- 
like processes, which are mostly opaque, the outer surface of the test is entirely 
naked, allowing the mantle and the viscera to be seen distinctly from the outside. 
There are no blood vessels traversing the substance of the test. 
Owing to the contraction of the mantle the internal body taken out of the test 
is considerably smaller than the entire animal (see the dimensions given above). 
There is a large space between the test and the mantle all over, the latter being 
separated from the test except round the apertures; in the posterior half of the body 
this space is especially large so that here the test is hollow inside. The internal 
body is, consequently, broader than it is long, 7.c. its greater diameter lies dorso- 
ventrally. Itis oval or almost spherical with the short siphons projecting from the 
dorsal and ventral edges of the broad anterior end (Pl. II, fig. 1). The branchial 
siphon is pointed anteriorly and somewhat ventrally, and is distinctly six-lobed; the 
atrial is directed anteriorly and is four-lobed. The lobes are triangular and pointed. 
The Manile is thin, almost membranous, and transparent. The musculature is 
only feebly developed, the bands being fine and distant, with the interstices filled up 
1 Dr. R. Hartmeyer, of Berlin, who is at present engaged in drawing up a complete list of the 
Ascidians for ‘* Das Tierreich ’’ , has told me in a letter that he will in that work relinquish the Order 
Aspiraculata and place the genus Hexacrobylus in the family Molgulidae. 
