PROCEEDINGS OF THE NATIONAL MUSEUM. 



Outside the umbrella portion of the stoniaeh branches, along the 

 lateral and posterior border of the carapace, lies a row of one-celled 

 skin "lands with tine awl-shaped ducts leading radially outward to the 

 very edge. These glands are more or less circular in outline and are 

 strongly flattened dorso-ventrally. Their granular contents are 

 arranged in fairly distinct rows radiating from the opening of the duct, 

 which is a little removed from one edge, sometimes near the center. 



This gives them somew^hat the appearance of miniature palm-leaf 

 fans laid side by side with their handles pointing outward. 



In foliaceus these side rows are broken by a comparatively wide 

 interval just opposite the base of the mouth, and the two groups thus 

 formed consist, respectively, of K) posteriorly and 4 anteriorly. There 

 are also in this species a pair of similar glands in front of the first 

 antennae, a pair at the inner corners of the lateral eyes, a pair behind 

 those eyes, and a group of four just in front of and one behind the 

 lateral branches of the stomach, but there are none in the al)domen. 



In the catostomi larvje no glands can be found anywhere in the hun- 

 dreds of preserved larva? now at disposal, and in the ^tizodetlu'i larva 

 no mention of them is made, nor do they appear in the figure. In the 

 americanm larva the glands are few in number, small in size, and are 

 scattered about promiscuousl}^ in both carapace and abdomen, with- 

 out any regularity. In the megalops larva, on the contrary, these 

 glands are much more highly developed, and the largest and best of 

 them lie in a row of six along either side of the abdomen some little 

 distance from the edge (^., fig. 9). In this species the rows along the 

 edges of the carapace are continuous and number 21 or 22 glands 

 each; there is an isolated group of 5 glands between the eyes at the 

 anterior border of the carapace, 3 in front along the edge, and 2 behind 

 them at the interior corners of the eyes. There are also on either 

 side a group of 3 placed diagonally behind the eyes, another group of 

 2 just in front of the side branch of the stomach, one over the side of 

 the stomach itself where this branch joins it, and a single large ellip- 

 tical gland at the outer end of the terminal joint of the basipod in each 

 of the swinnning legs. 



Although these glands are not found in the abdomen of the newly 

 hatched lar\a oi foliaceus (Claus) or catostomi, they appear there at a 

 later stage in development, and in the adult of all forms which have 

 been examined they are found scattered over the entire surface of the 

 l)ody, being gathered in groups in mnn}^ places, e. g., in the lobes of 

 the al)domen, the basal joints of the legs, etc. Their function has not 

 been explained by any author, but that they are morphologically sim- 

 ple glands there can be no doubt. Their ducts open at the surface of 

 the body, and under the influence of an alkaline solution a portion of 

 the contents of the body of the gland is discharged through the duct 

 in the form of globules (Leydig). Doul^tless they are capable of simi- 



