134 



ZOOLOGY. 



Order 1. Apoda.—Tlcie simplest apodous form is th* 

 Eupyrgus scaler Liitken, in which the body shows no 

 external signs of longitudinal muscles, though there ar© 

 five small ones, and is covered with spine-like, soft papillaa- 

 bearing calcareous plates. We have dredged it. 

 ^^ frequently on the coast of Labrador in shoal- 

 water. It has a circle of fifteen unbranched 

 tentacles, and is about one centimetre long. 

 It also occurs in Greenland and Norwegiaa 

 waters. Myriotrochus has a transparent skirt 

 dotted with minute white spots, which, when 

 magnified, appear to be wheel-like, calcareous 

 plates. It has a single Polian vesicle, and there- 

 is no respiratory tree nor Cuvierian appendages- 

 (Huxley). "We have dredged this beautiful 

 form (J/. Rinkii Steenstrup) in sand, in shoal- 

 water, on tlae coast of Labrador. A very com- 

 mon Labrador Holothurian is Cliirodota lave 

 Grube (Fig- 90). It lives in shallow, sandy, 

 \'\\ U \ retired bays, and is whitish-gray, with five dis- 



tinct muscular bands and scattered white spots, 

 which are calcareous, wheel-like bodies situatei 

 in the skin. 



Near Synapta, is Leptosynapta Girardii 

 (Verrill), our common east coast species, which 

 lives in sand at low tide. The body is very 

 long, and the animal when disturbed constricts 

 V'^siJ/ itsbody and breaks up into several pieces. The 

 skin contains perforated plates and anchor-like 

 bodies (Fig. 91). In this genus and those pre- 

 viously mentioned, constituting the suborder 

 Apneumona and family SynaptidcB, the sexes 

 Fie. 90.— c%i- are united in the same individual, and theie 



rodotaljuve. Half . . -, ■-, ^ -, 



natural eize. o, IS no respiratory tree, while the tentacles are 



moulh, clobed. . , t •,_ l ^ i i t . t 



Simply digitated or lobulated. 

 The next suborder, Pneumophora, forming the family 

 MolpadidcB, is characterized by having a respiratory tree. 

 In Caudina the skin is rough with calcareous pieces, the 



