PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 119 



The leugtli of the specimen (numbered 30334) is now 9.3 inches; 

 head 1.1; chest very nearly the same; greatest height of body, ^; vent 

 to tip of tail, l-^tr; dorsal from end of head, 5. 



I have thought it worth while to describe this lamprey in some detail 

 because of the interest which attaches to the locality and on account of 

 the slightness of our knowledge of I. castaneus^ to which our present 

 example is most closely related. 



United States National Museum, 



WasMngton, March 24, 1882. 



Since the above was written I have found and examined the types of 

 Ichthyomyzon hirudo and I. castaneus Girard. The first is 5 inches long 

 and is certainly congeneric with castaneus, from which it differs in the 

 number of mandibulary cusps. The maxillary tooth is tricuspid and 

 a few of the lateral teeth are bicuspid. Ichthyomyzon hirudo and J. cas- 

 taneus, therefore, show a departure from the type of the genus, which 

 is Petromyzon argenteus Kirtland; they have the dorsals continuous as 

 in argenteus, but the dentition is different. The maxillary cusps in hi- 

 rudo and castaneus are placed close together. The lingual teeth are pec- 

 tinate throughout, as in Lampetra tridentaia. We are called upon now 

 to decide whether Petromyzon argenteus Kirtland and Girard's two spe- 

 cies of Ichthyomyzon {hirudo and castaneus) are all members of the genus 

 Ichthyomyzon. In my opinion they are, but I should refer the three 

 species of Ichthyomyzon to Petromyzon. 



United States National Museum, 



June 14, 1882. 



NOTES OIV A €0I>L.ECTI01V OF FISHES FROITI JOHNSTON'S ISIiANI)^ 

 lNCl.ir»IN<J DESCRIPTIONS OF FIVE NE^V SPECIES. 



By ROSA SMITH awd JOSEPH SWAIRf. 



The specimens which form the subject of the present paper were ob- 

 tained in the spring of 1880 at Johnston's Island, by the captain of a 

 vessel belonging to the North Pacific Guano Company. A can of alcohol 

 was sent out on this vessel by Professors David S. Jordan and Charles 

 H. Gilbert during their stay on tlie Pacific Coast of the United States 

 in the interest of tbe United States Fish Commission. Johnston's Island 

 is located about 700 miles southwest of the Hawaiian Islands, and aj)- 

 proximates IT^* north latitude, 170° west longitude. This collection, 

 containing five new and many little known s^^ecies. Professor Jordan 

 has turned over to the writers for study. The specimens are now in 

 the United States National Museum. 



We are greatly indebted to Professor Jordan for the use of his library 

 aud for many valuable suggestions. 



