NATURAL SCIENCES OF PHILADELPHIA. 287 



ages pitchy, ventral spine slightly surpassing the posterior coxae : less honey- 

 yellow, tips of the tarsi piceous. 



Leugth to tip of membrane 7 millim. Humeral breadth 4 millim. 



Hab. Hong Kong, China. 



The generic name Pachycephalia, page 225, is preocupied and may be 

 changed to Hygia ; the species will then be Hygia opaca. 



The name Anacanthus, page 227, is also preocupied ; it may be changed to 

 Anacanthocoris. 



Descriptions of Nine New North American LIMN0BIACE2E. 

 BY BARON R. OSTEN SACKEN. 



Since the publication of my paper on the N. A. Tipulidce with short palpi (in 

 the Proceedings of the Academy for August, 1859,) my opportunities for col- 

 lecting have been very limited, and in consequence of this, the number of new 

 species discovered is not as large as I might have desired. 



The following descriptions embrace five new species found by myself, two 

 collected by Mr. Alex. Agassiz, in California, and two by Mr. Robt. Kennicott. 

 in the northwestern parts of the possessions of the Hudson's Bay Company. 



Several other new species in my collection I do not venture to describe, the 

 number of specimens not being sufficient to establish the specific character. 

 Among them, a Dicranoptycha, from California, deserves to be mentioned as a 

 matter of geographical distribution. 



I take occasion here to correct two errors which I discovered in the above 

 mentioned paper. 



First, That the measurement which I have used are tenths of an inch, and not 

 lines. I called them lines, because the line used in Russia is equal to one-tenth 

 of the Russian inch, which is the same as the inch used in England and America. 



Second, That my Limnophila pavonina is the Limnobia fascipennis Say. I had 

 failed for a long time to identify this species from Say's description, but am 

 positive now about this synonymy. 



DICRANOMYIA Steph. 



D. immemor. Silacea, thorace pleurisque vittis infuscatis, alis immaculatis 

 elongatis, valde angiitis, areola discoidali aperta ; long. 0-25 0'3. 



Ochraceous, vertex infuscated, palpi and antenna? brownish, second joint of 

 the latter stout; praescutum with three indistinct brown stripes; the inter- 

 mediate darker towards the collare ; pleurce with a brown stripe extending from 

 the base of the halteres, across the root of the wing towards the humeri ; hal- 

 teres pale, knob almost imperceptibly infuscated ; tergum somewhat brownish ; 

 feet pale yellow, tip of tibias and the tarsi infuscated; wings very narrow, 

 almost lanceolate, their basal, narrowed portion very long ; anal angle small, 

 hardly projecting; their color is subhyaline ; stigma elongated, pale, its outliue 

 indistinct posteriorly ; costal and subcostal veins yellow, the other veins brown ; 

 tip of the mediastinal vein a little beyond the origin of the petiole ; stigmatical 

 crcssvein near the tip of the subcostal vein ; radial area considerably longer 

 than the cubital one; the latter longer than the subapical one ; discoidal areolet 

 wanting, the space usually occupied by it not being closed by a crossvein ; 

 this space is narrow and elongated ; the fork, enclosing the second externome- 

 dial areolet is short and narrow ; axillary vein somewhat undulated. 



Numerous % and ^ specimens on a meadow near the Trenton Falls, N. Y., 

 in September (nob.) 



The general habitus of this species is different from the other Dicranomyice ; 

 its very narrow wings with their yellow costal and subcostal veins, forming a 

 contrast with the brown color of the other veins, make it easily recognizable. 

 The structure of its male forceps belongs to the same type with those of the 

 other species of the group. 



1861.] 



