150 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



The Larva of Aphrosylus. 

 Plate IV, Fig. 14. 



While observing the flies above described, it occurred to 

 me that their larval and pupal stages might be passed in the 

 salt water. A search for Dipteran larvae in the tufts of algae 

 on the rocks was rewarded by finding several forms, some 

 of which evidently belong to Nematocerous families. Two 

 specimens, however, measuring 3.5 and 5 mm. respectively, 

 taken at Pacific Grove during July, are undoubtedly Doli- 

 chopodid larvae, and I did not hesitate to assign them to 

 Aphrosylus. They are very probably the larva? of the com- 

 monest species, A. prcedator . My friend, Dr. H. P. John- 

 son, has recently given me another specimen, measuring 

 5.5 mm., taken in the same locality during December last. 



These larvae have the general characters that have been 

 noted for the Dolichopodidae by Beling, who has described 

 the larvae of six genera of this family (Psilopus, Neurigona, 

 Argyra, Porphyrons, Systeuus, and Dolichopus) 1 . They 

 are glistening white, tapering to a point anteriorly, and 

 less rapidly to the truncated posterior end, which is sur- 

 rounded by nine flattened lobes. These are arranged 

 as follows : One small lobe in the mid-dorsal line, two 

 larger and dorso-lateral, one on either side, two ventral, 

 largest of all and projecting furthest backward, and, 

 between the dorso-lateral and ventral lobe on either side 

 of the body, two small lateral lobes. The dorso-lateral and 

 ventral lobes are each provided with two fan-shaped tufts 

 of small bristles at their tips. The posterior tracheal open- 

 ings lie one on either side at the inner bases of the dorso-lateral 



1 Beitriig zur Metamorphose der zweifiuegeligen Insecteii. Arehiv f. Naturg. , Jahrg. 

 41, Bd. 1, 1875, pp. 31-57; and Beitrag zur Metamorphose zweifluegeliger Insecteii aus den 

 Familieu Tabauidae, I.eptidse, Asilidae, Empidae, Dolichopodidae, und Syrphidie. Arehiv 

 f. Naturg.. Jahrg. 48, Bd. 1, 1882, pp. 187-240. Other species are described by Brauer: Die 

 Zweifluegler des k. k. Museums zu Wien. 3. Systematische Studien auf Grundlage der 

 Diptereu-Larven nebst eiuer Zusammeustelluug von Beispielen aus der Literatur iiber 

 dieselben und Beschreibung ueuer Formen. Denkschr. Akad. Wien. Bd. 47, 18S3, pp. 19. 

 29-30. Taf. IV, figs. 72-75. This work also contains references to papers by v. Vollenhoven, 

 Brown, and Smith, on Ihe larvae of Mach&rium maritimum. I have not had access to the 

 contributions of these three authors. 



