On the Origin of the Organs o/Salpa. 123 



black, the third antennal joint less widely and abruptly- 

 dilated, &c. 



Elasmogasfer unicolor, sp. n. 



Pale uniform greyish brown, somewhat coarsely rugulose ; 

 antenna with tlie first, second, and third joints subequal in 

 length (fourth joint mutilated) ; membrane almost reaching 

 the apex of the abdomen, the lateral margins of which are 

 widely dilated ; rostrum almost reaching the anterior coxte. 



Long., (^ 17 ; max. lat. abd. 9 millim. 



Hab. East Africa, Nyassa (CotfereU). 



Differing from E. oji-icanus, Dall., the only other described 

 species of the genus, by the pale uniform colour, thus strongly 

 contrasting in the markings of the body, legs, rostrum and 

 antennffij &c. 



Homceoceriis Wealei, sp. n. 



Eeddish ochraceous, body beneath and legs somewhat 

 paler ; lateral angles of the pronotum strongly and sub- 

 acutely produced ; lateral margins of the abdomen dilated and 

 directed upwardly ; antennae with the basal joint longest, 

 second joint a little longer than the third or fourth, which are 

 subequal in length ; pronotum, scutellum, and corium with 

 coarse brown punctures ; extreme lateral edge of the abdomen 

 above ochraceous ; membrane pale shining brown ; rostrum 

 with the second joint a little longer than the third and sub- 

 equal in length with the fourth joint. 



Long. 14-15 ; lat. pronot. angl. 5 millim. 



Bab. South Africa {M. Weak) ; East Africa, Zanzibar. 



This species appears to find a systematic position between 

 the II. dilutus, Stal, and H. productus^ Stal. To the first it 

 is allied by the dilated abdomen, to the second by the produced 

 prouotal angles. 



XXIV. — The Origin of the Organs of Salpa. 

 By W. K. Brooks *. 



The Salpa Embryo. — Stated in a word, the most remark- 

 able peculiarity of the Salpa embryo is this — It is blocked 

 out in follicle cells, which form layers and undergo other 

 changes which result in an outline or model of all the general 



• From tbe 'Johns Hopkins University Circulars,' vol. xii. no. 106, 

 pp. 98-97. An abstract of Chapter XIV. of ' A Memoir on the Qenus 

 Salpa,' which ig now in the press. 



