370 



BULLETIN OF THE BUREAU OF FISHERIES. 



iug. 8; 1, in poor condition; no spines certainly made 

 with spines. 



17. Distornum tenue Linton. 

 1902. — July 17, 1, not in good condition. 



out, but specimen looks as if it had been armed 



18. Gasterostomum gracilesfimx Rudolphi. 

 1902.— July 17, 1. 



See under Menidia, Ityluswus marinus, etc. 



19. Microcotyle sp. [Figs. 147-159.] 



1902. — Aug. 8, 1, probably from .trills; fragment, the posterior aucker-bearing portion missing. 

 Figs. 147 and 14s. were sketched from this specimen. The cirrus hooks formed an elongated clusterand 

 are shown diagrammatically in fig. 148. Dimensions, life, in millimeters: Length 1.85; breadth at 

 anterior end 0.12; greatest breadth 0.42; length of cirrus hooks 0.025. The specimen was very 

 fragile. It was broken while it was being examined, and destroyed in an attempt to mount the 

 fragments permanently. Aug. 16; 2, from gills. Aug. 22; 1. These specimens were complete and 

 belong to this genus. 



A mounted specimen has the following dimensions in millimeters: Length of body proper 1.20; 

 of posterior sucker-bearing portion 1.12; diameter through anterior suckers 0.10; greatest diameter 

 0.37; diameter of posterior sucker-bearing part 0.1*; suckers at anterior end, length 0.051, breadth 

 0.039; pharynx, length 9.42, breadth 0.036; posterior suckers number about 50 pairs, each sucker 

 0.042 by 0.021, the longer diameter transverse to axis of body; length of cirrus hooks about 0.015. 

 The cluster of hooks on the cirrus is somewhat triangular, and each hook seems to be two-forked 

 at the base. [Fig. 150.'] The posterior suckers arc provided with a chitinous framework, which is 

 imperfectly shown in fig. 149. 



PARASITIC COPEPODS. 



20. Lernanthropus sp. From gills. 



1901. — July 10, 3, from gills. While I have not undertaken to identify the parasitic copepods, I 

 here record an unusual form. The most striking feature was the possession of a pair of forked leaf-like 

 appendages. These appendages were flexible and were frequently bent dorsally by a convulsive 

 movement. The inner ramus of each appendage was the more active of the two and kept up a 

 rhythmic movement which appeared to be directly concerned with the circulation of the blood. At 

 each such movement the blood was driven along the marginal vessel toward the body, at the same 

 time the blood left the marginal vessel of the outer ramus. As soon as the convulsive contraction 

 was over the appendage relaxed by its own elasticity and the blood returned to its vessels. The 

 general color effect is dark reddish-brown. The blood is red. The appendages made out are: 1, a 

 pair of small antenna; 2, a pair of hooked mandibles; 3, two pairs of maxillae; 4, a pair of appendages 

 on the thorax which terminate in horseshoe-shaped suckers; 5, forked appendages at posterior end 

 which function as gills. The tail is forked at the tip with two brown chitinous sucking-disks. Egg 

 sacs 2, cylindrical, dark brown, protruding posteriorly, nearly equaling length of body. 



1902. — Aug. 8, 1, female, with elongated pinkish egg-chains. Aug. 12; 1. Aug. 16; 2. Aug. 22; 

 14. Aug. 26; several, males and females. These have been turned over to Prof. C. B. Wilson. 



Rachycentron canadus, Cobia, "Cabio" (Beaufort). 



All the fish examined in 1901 small, 16 to IS inches in length. 



