140 BULLETIN 168, UNITED STATES NATIONAL MUSEUM 



Jsotoma {Isoto77ia) grandicepsr. 



422. Eyes of left side, X 347. 



423. Base of antenna, postantennal organ, and adjacent eyes of left side» 



X 333. 



424. Sense organ of third antennal segment of right side, X 1,120. 



425. Right hind foot, X 653. 



426. Right mucro and end of dens, X 653. 



427. Dorsal setae of third abdominal segment, X 347. 



Plate 37 

 Ifoioma (Isotoma) viridis: 



428. Typical form, X 20. 



429. Eyes and postantennal organ of left side, X 185. 



430. Sense organ of third antennal segment of left side, X 490. 



431. Left hind foot, X 395. Specimen from Massachusetts. 



432. Left hind foot, X 295. Specimen from Greenland, 



433. Concave aspect of unguis, X 395. 

 Jsotoma {Isotoma) viridis riparia: 



434. Specimen, X 25. 

 Jsotoma (Isotoma) viridis delta: 



435. Specimen, X 25. 

 Jsotoma (Isotoma) viridis pomona: 



436. Specimen, X 30. 



Plate 38 

 Jsotoma (Isotoma) viridis: 



437. Left mucro and end of dens, X 576. 



438. Left aspect of tenaculum, X 218. 



439. Dorsal setae of third abdominal segment, X 171. 



440. Spinulate seta, X 153. 



441. Last four abdominal segments, X 52. 

 Jsotoma (Isotoma) subviridis: 



442. Eyes and postantennal organ of left side, X 297. 



443. Sense organ of third antennal segment of right side, X 594. 



444. Left fore foot, X 594. 



445. Left mucro, X 935. 



446. Left mucro, X 935. 



447. Right mucro, X 935. 



448. Right mucro, X 935. 



449. Dorsal setae of second abdominal segment, X 153. 



Plate 39 

 Isotoma glauca: 



450. Tenaculum. From a pencil drawing by Packard. 

 Isotoma tridentata: 



451. Right hind foot, X 520. 



452. Lateral aspect of right mucro, X 1,300. 



453. Dorsolateral aspect of right mucro, X 1,300. 



454. Dorsal aspect of right mucro, X 1,300. 

 Isotoma aspera: 



455. Claws. From Bacon. 



456. Left mucro. From Bacon. 

 Proisotoma laguna: 



457. Eyes of right side. From Bacon. 



458. Postantennal organ. From Bacon. 



459. Claws. From Bacon. 



460. Furcula. From Bacon. 



461. Mucro. From Bacon. 



