STATE GEOLOGIST. 169 



If this form be worthy a distinctive name, it may he called 



Sp. 2. Cantliocamptns tenuicaudis, (Sp. n.) 

 (Plate 0. Figs. 15 and 16.) 



? Sp. 3 . Canthocaiiiptus brevipes, Sars. 



This small form is almost certainly the young stage of some other 

 species; yet I transcribe the description. 



"Corporis forma et magnitudine C. pygmseo non dissimilis. Segmenta abdominalia 

 vero postice magis attenuata seriebusque aculeorum destitiita. Rami caudales elongati 

 duplo longiores quam latiores, setis apicalibus brevisculis parumque divergentibus, ei- 

 teriore dimidiam longitudinem interioris non attlngente. Operculum anale absque 

 dentibus. Antennae 1-nii paris breves, articulis ultimls duobus in unum confluentibus 

 artlculum. Pedes natatorii brevissimi, ramo exteriore intus setis destitute, iuteriore 

 biarticulato in pedibus 1-mi paris longitudinem|exteriorissequante, in sequentibusmulto 

 breviore. Pedum 5-tl paris articulus basalis intus in proeessum foliiformem, sat mag- 

 num et angustatum, articulum ultimumelongato-ovatum aliquanto superantem, exit. 

 ■Color albidus. Longit. parum supra '/imm." 



Sp. 4. Cantliocaniptiis crassus, Sar3. 



Robust; segments margined with pectinate bristles. Caudal 

 stylets oval, contorted, constricted at the base. Antennae thick, 

 densely covered with long setae. Fifth feet with long setae; basal 

 process rather small. All the feet excepting the first, with bi- 

 articulate inner rami. Length 0.75 mm. 



Sp. 5. Canthooaniptus trispiuosus, Brady. 



(Plate 0. Figs. 6—14.) 



This species with the last and next has all the feet save the first 

 with bi-articulate inner rami. Very near the next, from which it 

 differs in the form of the fifth foot of the female, which has the 

 basal process smaller, bearing only three spines, while the next has 

 six, the second joint being longer and narrow. The male is un- 

 known. Not yet identified in America. 



Sp. 6. Canthocamptus uortliuiubricus, Brady. 



Body robust; antennae long as first segment, nine-jointed; man- 

 dibular palp minute. In the male the inner branch of the third foot 

 is three-jointed and dactylate, as in C. minutus. 



