1903.] NATURAL SCIENCES OF PHILADELPHIA. 387 



the body. In Floscidaria the flame cells are readily found, but it is 

 very difficult to find all the connections of the ductules and tubules. 



Cilia are found only within the flame cells, as a long intracellular tuft 

 or flame, and these terminal cells appear entirely closed off from the 

 body cavity; they have also no connection whatsoever with the lateral 

 antennae (as one observer had supposed). 



Organs of prohlcmatical significance.— In conklini there is found a 

 large transparent structure {GL, fig. 25) immediately below the hypo- 

 dermis (and peripheral to the other internal organs), at the junction of 

 the corona and trunk. It is lobed and forms here a ring just beneath 

 the hypodermis, and attached to it. It appears to be gelatinous. Prob- 

 ably this is a glandular structure, and the dorsal gland of Stephano- 

 ceros may be homologous. 



In coronetta a vesicular dorsal, hypodermal structure (D.GL, fig. 23). 

 probably a gland, is found just below the dorsal sense-organ. 



Nervous system, sense-organs.— In all the species the cerebral gano-li„n 

 (Cer., figs. 20, 22, 23, 25, 28) lies deep below the hypodermis, on the 

 dorsal surface of the vestibulum; it is elongate from side to side and 

 composed of numerous small nerve cells. The nerves arising from it 

 were studied most thoroughly in campanulata. In this species"(figs. 28 

 32) the gangUon seen from the side shows quite clearly a distinction 

 between a dorsal and a ventral portion. From the dorsal side two 

 nerves pass anteriorly to the dorsal sense-organ (D.Sens.O.), and a 

 single nerve in the median line posteriorly to end on the hypodermis. 

 From the anterior edge of the ventral portion of the ganglion a laroe 

 nerve fiber passes antero-laterally to each lateral sense-organ (L.Sci^s. 

 0.) ; two smaller nerve pairs pass posteriorly from its posterior margin'; 

 and from its lateral margin a pair of large nerves on each side down- 

 ward and backward along the surface of the proventriculus. These 

 nerve fibers could be seen more clearly in fife than upon stained prep- 

 arations; methylene blue staining gave no positive results. 



In coronetta there is found on the sides of the corona a single pair of 

 small red eyes {E. , figs. 22, 23) . In some adult individuals o'f ambigua 

 (fig. 20), but not in all, were found a number of eyes, up to five in all 

 on the dorso-posterior part of the corona; these have an irregular ar- 

 rangement, and each consists of a few large red pigment granules. 

 Campanulata and conklini have no eyes in the adult stage. ^ All the 

 species possess an unpaired dorsal {D.Sens.O., figs. 20, 22, 25, 28) and a 

 pair of lateral sense-organs {L.Sens.O., figs. 20, 23, 27, 28) (antennse) 

 upon the corona, each bearing a tuft of long sense hairs. In campanu- 

 lata the dorsal organ {D.Sens.O., fig. 32) was found to consist of from 



