Notes on the morphology of the Tunicata. 583 



These tubular processes are interesting in connection with the 

 root-like processes from the ectoderm seen in those Molgulas which 

 have no tadpole, but have an abbreviated development. Two years 

 ago in Casco Bay, Maine, I obtained material for the study of the 

 development of a small Molgula, apparently M. pellucida^ in which 

 there is no free swimming tadpole. Comparison of the root-like 

 processes in the embryos of this species with the tubular evaginations 

 of the ectoderm of Molgula manhattensis indicates that they are 

 probably the same thing. Molgula manhattensis has a well developed 

 tadpole in which, at the time of metamorphosis, from five to ten 

 tubular ectodermal processes develop similar to those which develop 

 at a little earlier stage, in those species with abbreviated development. 

 KiNGSLEY says^): "The processes which grow out from the body 

 are generally considered as the means by which the embryo attaches 

 itself, but in Molgula manhattensis this is certainly not the case. At 

 no time can these processes be seen to pass through either of the 

 envelopes of the body, and consequently they cannot serve as the 

 points of attachment. They seem to me to be merely the remnants 

 of the organs which in some ancestor were possibly for fixing the 

 young Tunicates in a manner analogous to that presented by the 

 antennae and cement glands of the cirripedia, but which have lost 

 this capacity, and which have not entirely disappeared through disuse. 

 After becoming attached the processes grow larger and longer and 

 then are finally absorbed." I have not traced their development and 

 have no evidence that any of the tubular processes in the adult are 

 genetically connected with those of the metamorphosing larvae, but 

 their general appearance and histological condition would indicate 

 that they are organs of a similar nature. It seems probable, there- 

 fore, that any explanation of these structures based only on their 

 relation to the needs of the period of development must be in- 

 adequate, since the adult finds use for similar organs. 



Section VIII 2). 

 Bostrichohranchus molgitloides n. sp. 



In soft muddy bottom in Buzzards Bay, near Wood's Holl, Mass., 

 ViNAL N. Edwards, the collector for the United States Fish Commis- 



1) KiNGSLEY, 1883, p. 446 and 447. 



2) It is only since this paper has been in press that I have had 

 access to Traustedt's original description of B. manhattensis. I thought 

 at first my specimens represented a new genus and so named them 



