THE LEECHES OF MINNESOTA 99 



cocoons. Chiefly semi-permanent parasites on fishes, sometimes on 

 crustaceans. Nearly all are marine. Piscicola and closely related 

 genera only are found on fresh water fishes. 



Genus Actinobdella Moore. 



Rather slender and elongated, moderately depressed or half 

 round. Oral sucker slightly developed ; caudal sucker large, deep, 

 and provided with a circle of numerous marginal papillae and glands. 

 A few dorsal papillae, some median. Complete somites of six unequal 

 rings. Eyes, one pair on III, united. Pharyngeal salivary glands 

 diffuse ; gastric caeca seven pairs, branched. Genital orifices separated 

 by four rings; sperm ducts lacking long loops, moderately compact. 

 Small blood-sucking leeches, probably parasitic on fishes. 



Actinobdella inequiannulata Moore. 



(Plate III, fig. 19,20.) 



Actinobdella inequiannulata Moore (1901) 



Description— The collections from Lake Pepin included an ex- 

 ample of this very interesting species, the second one known, which 

 enables me to confirm and extend, and in some particulars to correct, 

 the original description. This additional knowledge renders more 

 evident than before the position which Actinobdella occupies on the 

 border between the two families of Ichthyobdellidce and Glossi- 

 phonidce, in fact the mere numerical weight of its characters as now 

 known point rather toward an alliance with the latter. As I hope soon 

 to have sufficient material to permit a thorough anatomical study the 

 discussion of its zoological position can best be postponed. The Lake 

 Pepin specimen measures 12 mm. in length and has nearly the form 

 of the tvpe except that the middle region of the body is somewhat 

 widened. The following description is nearly a transcript from the 

 original with such changes and additions as further knowledge neces- 

 sitates. 



The form is slender and depressed throughout, with the dorsal 

 surface convex, the ventral flat and the margins sharp. The breadth 

 is nearly equal or somewhat greater in the middle region, but con- 

 tracts suddenly at the posterior end to constitute the narrow pedicle 

 of the conspicuous caudal sucker, and at the anterior end tapers gently 

 to the broadly rounded upper lip. 



There is no conspicuously expanded anterior sucker or head as 

 in typical ichthyobdellids, but this end of the body is formed exactly 



