MOLGULA. 35 



Genus 4. MOLGULA Forbes, 1848. 



[Ascidia (pars) 0. F. MULLER Zool. Dan. I (1788), p. 42.] 

 Molgula FORBES in Brit. Moll. I [1848], p. 36; ALDER & 

 HANCOCK in Trans. Tyneside Nat. Field Club, I [1848], 

 p. 195; WOODWARD Man. Moll. [1856], p. 337; GOSSK 

 Man. Marine Zool. II [1856], p. 35; H. & A. ADAMS 

 Gen. Recent Moll. II [1858], p. 590; [ALDER in Ann. 

 Nat. Hist. (3) XI (1863), p. 158]. 



Bodi/ ovate or globose, generally covered with glan- 

 dular fibrils by which the animal accumulates a coating 

 of sand or shells and in some species attaches itself to 

 other bodies. Test usually thin, fibrillous, and nearly 

 colourless. Branchial aperture 6-lobed; at rial aperture 

 4-lobed. Tentacular filaments more or less pinnate or 

 branched. Branchial sac with longitudinal folds, the 

 meshes irregularly convoluted. Stomach and intestine 



O / 



lateral. Reproductive organs on both sides, those of 

 the right side situated above the lower intestinal loop. 

 The members of this genus are comparatively small 

 and globular, with, usually, a coating- of sand or of 

 fragments of shells or stone. They have rarely any 

 flattened surface of attachment like that of Ascidia, 

 and consequently they are usually assumed to be free. 

 This, however, may to some extent be questioned. 

 The surface of the test is supplied witli numerous 

 hair-like processes or delicate branched fibrils. These 

 adhere with considerable firmness to the more gritty 

 matters mixed with the sand or fine mud in which 

 these animals are undoubtedly to some extent buried. 

 They thus become fixed in their position, and on re- 

 moval bring along with them a coating of the attached 

 particles. This would appear to be their usual habit. 

 In. some instances, however, they become adherent, 

 through the agency of their external fibrils, to the 

 surface of hard bodies, such as the exuviae of mollusca, 

 and cover the exposed portion of their test with the 

 usual fragmentary matters. 



