1903.] NATURAL SCIENCES OF PHILADELPHIA. 637 



Backward from the broadest portion, the animal's body tapered gradu- 

 ally, ending l)ehind in a point. 



This species is placed in the genus Hoplorhynchus on account of its 

 close resemblance to H. actinotus Leidy and its occurrence in a centi- 

 pede related to Scolopocryptops, the host of the latter. 

 Trichorhynchus lithobii n. sp. PL XXX, fig. 18. 



This animal, which is apparently specificalh^ distinct from any of 

 the other gregarines parasitic in Lithobius, was found in a specimen of 

 that centipede from Raleigh, N. C. An epimerite was not seen. The 

 protomerite was subcordiform, and displayed in front a differentiation 

 the exact nature of which could not be determined. The deutomerite 

 varied considerably in shape, the animal being quite polymorphic. 

 Both epicyte and sarcocyte were distinct and of about equal thickness. 

 The septum was thick and curved backward. The entocyte was not 

 dense; the nucleus large, with several karyosomes. The largest indi- 

 vidual seen was 195 microns long. 



Figs. 20 and 21 show a small gregarine frequently encoimtered in 

 Scolopocryptops scxspinosus Say. Fig. 21 is doubtless that of a very 

 young specimen which has been loosened from its original attachment 

 by the breaking up of the host intestine upon the slide. The three 

 segments are all marked out. It seems almost certain that this figure 

 represents a young Hoplorhynchus actinotus Leidy. The animal shown 

 in fig. 20 was very like the other in general appearance and had the 

 paleness characteristic of a young animal. There was, however, no 

 epimerite, nor did the individuals seen show any indications of recent 

 mutilations. H. actinotus may retain the epimerite mitil it reaches a 

 length of 700 microns, whereas the animal here figured was only 45 

 microns long. The observed facts are capable of two interpretations. 

 The one is that H. actiiiotus is to a certain extent dimorphic ; that is, the 

 epimerite may be lost very early or it may be retained until the animal 

 has reached nearly or quite the maximum size. The other is that while 

 fig. 21 represents a young individual of H. actinotus, fig. 20 is that 

 of a different species. The matter is, however, one best held under 

 advisement until additional facts are obtained. 



There follow certain addenda, mostly with regard to the cysts and 

 spores, to the characters of species previously described. 

 Actinocephalus harpali (Crawley). PI. XXX, fig. 14. 



Gregarina harpali Crawley (1903), p. 49, PI. 1, figs. 1—1. 



To the characters given in my original description of this species 

 add: 



