40 BRITISH ENTOMOST&ACA. 



I suspect it to be their only one, and that they are merely 

 aquatic, and never turn to flies, as many insects found ill 

 water do." (p. 72.) 



Linnaeus had, long previously to this, in his ' Fauna 

 Suecica,' 1746, noticed an animal which may, perhaps, 

 be the same as this. He inserts it at the end of the 

 volume, as if in doubt where to place it, and indeed de- 

 scribes it as a larva. He asks, "An larva Ephemerae?" 

 but at the same time particularly mentions the female as 

 possessing a small, yellow, shining globule, adhering to the 

 abdomen, and which, he says, is perhaps the ovary, ready, 

 as soon as the metamorphose is completed, to become 

 eggs. 



A few years after this, Schceffer, while studying the En- 

 tomostraca, discovered, in a pool of water near Ratisbon, 

 a number of specimens of an " aquatic insect," very similar 

 to the species found in England. He published a long 

 description of it in 1752, under the name of Apus pisci- 

 formis, which he afterwards, in his ' Element. Entomol.,' 

 changed to JBrancMjsus pisciformis. Schceffer appears to 

 have dissected it very carefully, and gives figures of various 

 parts, as observed by the microscope ; but neither in his 

 description nor his figures does he take the slightest notice 

 of the peculiar complicated apparatus attached to the head, 

 which characterises so strongly the genus Chirocephalus, 

 and which, though roughly executed, is decidedly ex- 

 hibited in the figures given by King. Linnaeus, in the 

 meantime, having ascertained that his opinion, as to the 

 insect which lie mentioned in the ' Eauna Suecica' being 

 a larva, was erroneous, described it, in the tenth edition 

 of the ' Systems Naturae,' as a Crustacean, under the name 

 of Career stagnalis. His description is so short that it 

 is impossible now to ascertain whether the animal he men- 

 tions possessed this peculiar apparatus or not ; but Dr. 

 Shaw found it again in England, and published a length- 

 ened notice of it in the first volume of the 'Linnean 

 Transactions' for 1791. He does not state the locality 

 where it was found, but he describes and figures with 



