40 GENUS FIROLOIDA, 



extremity thicker, and truncated; dorsal fm equidistant 

 between the eyes and the nucleus, 



Plate 2, fig. 2. a. small specimen; b. nucleus and ovi- 

 duct magnified. 



Inhabits near Martinique^ taken in March 1816. 



Oviduct shorter, perhaps broken, thicker; posterior 

 part of the nucleus furnished with small oviform globules. 

 Length of the body seven lines to one inch and a half. 



3. F, aculeata. Body subequal^ glabrous, hyaline, 

 wrinkled above the eyes. Dorsal fin equidistant from the 

 extremities, longer behind. 



Plate % fig. 3, magnified. 



Taken April 26, 1816. 



Nucleus suboval — eyes conspicuous; one elongated, 

 gelatinous point beneadi the eyes, and another, nmch 

 shorter, before them — oviduct none. 



I here add some anatomical explanations, accompanied 

 with figures of a species of the genus Firola, described in 

 the preceding number. 



opiate 2, fig. 4. represents a firola magnified and opened 

 on the side. a. a, a, gelatinous, exterior substance of the 

 body, which at q remains entire, h. b. b. peritoneum 

 opened, and entire at g, c, diaphragm, d, anterior gang- 

 lion, c. posterior ganglion, f, nucleus; it is laid bare 

 of the peritoneum, to exhibit a granulated appearance, on 

 its superior part; very like grains of Indian corn (Zea), 

 j&. branchia. h. h, artery, u i, branch of the artery. 

 A\ intestine. /. /. /. caudal muscles, n. muscles of the 

 jdorsal fin. 7n. cup of tlie dorsal fin. o. o. radicles of the 

 dorsal fin. r. r. two small filiform tubes, opening into 

 the posterior part of the peritoneum, and connected with 



