514 



PROCEEDINGS OF THE NA TTONAL MUSEUM. 



VOL. XXVIII. 



Both pairs of glands are dark brown in color, but while the 

 first pair are partially or wholly concealed among the muscles and 

 appendages of that portion of the carapace, the second pair stand out 

 conspicuously in dorsal view, since they are close to the dorsal sur- 

 face. In some species they are quite small and shaped like a comma, 

 the large, rounded body tying upon the upper surface of the intestine, 

 while the curved tail bends around laterally to the ventral surface of 

 the intestine, where it gives off a duct leading to the posterior end of 

 the stomach. 



This is the condition in Lepeophtheirus pectoralis, while in Caligus 

 rapax the gland is much larger, horseshoe-shaped, and entirely free 

 from the intestine, though lying close to it. The duct here is given 



off from the outer arm of the 

 horseshoe, turns downward and 

 then forward to enter the stom- 

 ach (fig. 22). 



In many of the other species 

 and genera these glands are of 

 a decidedly different shape if the 

 brown bodies visible in the tho- 

 racic areas are &ny criterion. 

 Thus by a reference to the plates 

 of the new species here published 

 it will be seen that in Lepeoph- 

 theirus edivardsi, L. longipes, 

 L. chilensis, and L. parviventris 

 as well as in Caligxis pelamydis 

 these brown spots show as quite 

 regular oval or elliptical bodies 

 flattened on the inner sides. In 

 Gloiopotes ornatus they are very 

 regular ellipses without being 

 flattened at all. In Caligus honito they are very small and seem fused 

 on the mid line into a bean-shaped body. In three species of Caligus — 

 latifrons, exilis, and aliuncus — they are comma-shaped with the small 

 end pointing forward, and in the last species also outward. In Caligus 

 mutdbilis the}' are even unlike in the two sexes, having a club-shape 

 in the male, the two clubs being strongly curved with their small ends 

 toward the front and their concave sides toward each other. In the 

 female they have the shape of a spherical triangle, the apices pointed 

 backward, with a small spherical enlargement on the outer side at 

 about the center. 



In Lepjeoj>htheirus hippoglossi they have the form of paragraph 

 marks placed back to back. In the male of Caligus schistonyx they 

 show up as hatchet-shaped bodies, widely separated, and the handles 



Fig. 22.— Posterior digestive glands of Caligus 

 rapax. d, duct; g, gland; m, muscles; s, stomach. 



