544 MAYNARD M. METCALP, 



are no cells in the lumen of the gland. The epithelium of the duct 

 is composed of pavement cells. 



I have been unable to tell whether the single large chamber in 

 this species is homologous with both of the ventro-lateral chambers 

 of other species, or with only the right one ; more probably the latter. 



I have had no opportunity to section the solitary form of this 

 species. 



lasts cordiformiS'Zonaria Q. et G. -Pall. 



The solitary form of this species has the ventro-lateral chambers 

 of the gland and their ducts normally developed, except that the 

 chambers are small. No ventro-lateral ganglia are present, unless, 

 as is quite possible, the larger-celled ganglia are represented by the 

 great lateral appendages of the ganglion, which I have described in 

 another paper ^) as containing cells which resemble the irregular rod 

 cells found in the larger and smaller eyes of many species of Salpidae. 



The chain form shows no traces of any neural gland or ventro- 

 lateral ganglia. 



lasts costata-tilesii Q. et G.-Cuv. 

 Plate 38, Fig. 60. 



I have not sectioned the solitary form of this species. In the 

 chain form we have a single large chamber in the neural gland, as 

 in lasis hexagona. This underlies the whole brain. Its duct opens 

 to the pharynx as in the latter species, by a great aperture somewhat 

 to the right of the median line 2). In the chamber of the gland the 

 endothelium of that wall which lies next to the brain, is columnar, 

 as in lasis hexagona. There are no cells in the lumen of the gland. 



There are no ventro-lateral ganglia. 



JPegea scutigera-confoederata Cuv.-Forsk. 



In this species the chain form shows the neural gland typically 

 developed, also a single pair of large-celled ventro-lateral ganglia. 

 1 have not sectioned the solitary form. 



1) Of. Metcalf, 18952, IV. 



2) My description of this aperture in a former paper (Metcalf, 

 1893 2) was slightly inaccurate. 



