REPORT ON THE TUNIC ATA. (51 



Eugyra differs from Molgula chiefly in having no true folds in the branchial sac. 



and in having only a single genital gland, placed beside the intestine on the left side of 

 the body. 



The following shows the genera of the family in a tabular form : — 



Molgulim:. 



Molgula. Ascopera. 



Ascopera, Herdman. 

 Ascopera, Herdman, Preliminary Report, Proc. Roy. Soc. Ediu., 1S80-S1, p. 238. 



Body more or less pyriform, pedunculated, attached. 



Test thin, between membranous and leathery in texture, having no adhering sand 



and no hair-like processes. 

 Branchial Sac with seven folds on each side. Stigmata straight or curved, but 



not arranged in spirals. 

 Tentacles compound. 

 Genitalia developed on both sides. The gland on the left side lies ventrallv to 



the rectum. 



This genus is closely allied to Molgula, and has the chief characters of the family \ ery 

 well marked. The branchial aperture is sixdobed, and the atrial four-lobed ; the 

 branchial sac has seven longitudinal folds on each side ; the tentacles are compound, and 

 a distinct renal organ is present, lying on the right side posteriorly to the genital gland. 

 The external appearance, however, is not suggestive of a Molgula. The body is pedun- 

 culated, and was evidently attached by the posterior end of the short stalk while the 

 outer surface of the test is not incrusted with sand and bears no hair-like processes. 



The arrangement of the stigmata in the branchial sac differs considerably in the two 

 species, but in neither are they disposed in spirals, as no true infundibula are present. 



The intestine lies upon the left side of the branchial sac and runs an tero- posteriorly ; 

 it has a large genital gland at its ventral edge, while the other genital gland is situated 

 in the centre of the right side, projecting from the inner surface of the mantle. 



