NO. 1788. NORTH AMERICAN EROASILID.E— WILSON. 359 



Total length 2.29 mm. Ceplialothorax 0.38 mm. long, 0.78 mm. 

 wide. Length of trunk 1.8 mm., width 2 mm. Length of egg-strings 

 L75 mm. 



Color, a uniform cartilage gray. 



(corpulentus, large, thickset.) 



There is but a single lot of this species, which was taken from the 

 northern swell-toad, Splieroides maculatus, at Woods Hole, Massa- 

 chusetts, and is numbered 38619, U.S.N. M. It includes three 

 females, two of which bear egg-strings. It can be readily distin- 

 guished from impressus by the fact that the body is nearly circular in 

 outline instead of oblong; it overhangs and entirely conceals in dorsal 

 view the genital segment and abdomen, and there are no pits on either 

 the dorsal or ventral surface. Whether it is as common as the other 

 species can not be determined, since only a few fish have ever been 

 examined for the parasite. 



TUCCA VERRUCOSUS, new species. 



Tucca impressus, Nordmann, 1864, p. 491, pi. 6, figs. 7 to 10. 



The species described as T. impressus by Nordmann (1864) is cer- 

 tainly distinct from the one so designated in the present paper (p. 354). 



It follows that either Nordmann's species or that of the present 

 author is new to science. They can not both be identical with Kroyer's 

 T. impressus. After a careful examination of the original descrip- 

 tions of Kroyer and Nordmann, together with the figures which 

 accompany them, it seems most probable that Nordmann was 

 describing a new species, while the present author had secured new 

 specimens, including both sexes, of Kroyer's species. 



In evidence of this we fuid that Nordmann's description difl"ers 

 from Kroyer's in many important particulars: 



1. He does not find the "seitlichen Einsclmitte" which Kroyer 

 distinctly shows upon the enlarged posterior body. 



2. He claims that the posterior portion of this part of the body, as 

 well as the abdomen, are represented by Kroyer as much too broad. 



3. He finds a pair of six-jointed first antenna) projectmg from the 

 anterior margm of the ceplialothorax which he says Kroyer ''over- 

 looked." 



4. There are no traces of the two-jointed attachment organs 

 described by Kroyer on the inner margin of the side lappets, and he 

 thinks Kroyer was really looking at the thickened edge of the lappets 

 themselves. 



5. He finds the dorsal and ventral surfaces of the body, including 

 the central portion of the ceplialothorax, but not the lappets, covered 

 with small conical "Warzen," v/hicli were not noticed by Kroyer. 



None of these particulars were likely to have escaped Kroyer's 

 attention, except possibly the last one. He certainly would not have 



