Genus Hydaticus. 219 
line of margination a little behind the shoulder; near the base a 
narrow longitudinal marking of black extends midway within the 
flavous band for about one-fifth of the length of the elytra. I 
agree with my friend Dr. Schaum that the form before us can 
only be viewed as an interesting and eccentric variety of H, vit- 
talus, although in a considerable series of examples of this com- 
mon species I possess no individuals which offer a connecting link 
between it and the normal pattern. 
17. H. parallelus, n. sp. 
Oblongo-subovalis, parallelus, punctato - striatus, rufo-niger, 
nitidus: capite impunctato, fusco, ad apicem rufo, rufa etiam 
macula transversali brevi inter oculos (hee fortasse aliquando 
maculis duabus contiguis divisa est); ¢horace lateribus rotun- 
datis, anticé profundé excavato, basi subtiliter sinuato ; juxta 
Jatus anterius fossa transversalis punctis minutis ornatur; ad 
latera et basin versus rime longitudinales velut acuductz 
apparent; facies rufa vel rufo-brunnea, macula ad medium 
transversd nigro-fusca adumbrata; sculello triangulari, levi, 
nigro; elytris parallelis, subelongatis, seriebus 2 undique 
punctorum (punctis sparsis et minutis), fusco-rufis, ad latera 
rufo-irroratis, marginibus ipsis omnino rufis: corpore sublus 
fusco; antennis flavo-rufis ; pedibus flavo-rufis, posticis rufo- 
fuscis. 
Long. corp. lin. 63; lat. lin. 3}. 
I believe that this species is distinct from Hydaticus Capicola of 
Aubé, though the foregoing diagnosis will show that the two are 
closely allied ; and I am confirmed in this opinion by a note which 
I made some years ago, that the species before us was almost 
(probably quite) identical with a MS. species in the British 
Museum Collection, Fordii* (Brit. Mus. Cat. Hydrocan. p. 18). 
Now Fordiit (ranked, by the by, accidentally in the British 
Museum Catalogue as a Colymbetes, instead of a Hydaticus) 
was thus nained by Dr. Schaum as a new species when he had 
also before him H. Capicola, Aubé. I have thus his excellent 
authority for erecting it into a separate species. The insect 
before us is more parallel; it is also larger in size, and the elytra 
are completely fuscous-black, the sides only being narrowly 
sprinkled with rufous; not “ elytris rufo-testaceis, crebre nigro- 
irroratis,”’ as in Aubé’s description of his insect. 
The range of the habitat of H. parallelus is, however, open to 
* Unfortunately, in the Museum this species has been for the time mislaid. 
T am thus unable to verify my note by a second examination. I have no reason, 
however, to doubt its accuracy. 
